tacoma16_engine

NEW FEATURES – 2GR-FKS ENGINE 119

JSERPENTINE BELT DRIVE SYSTEM

1. General

D Accessory components are driven by a serpentine belt consisting of a single V-ribbed belt. It reduces the
overall engine length, weight and number of engine parts.

D An automatic tensioner eliminates the need for tension adjustment.

*7 *2

*1 *6
*2
*5
*3 *8 *4

26L0EG127

" Text in Illustration A *2 Belt Idler No. 2
*4 Air Conditioning Compressor Pulley
*1 Power Steering Pump Pulley *6 Generator Pulley
*3 Crankshaft Pulley *8 Belt Idler No. 1
*5 Idler Pulley for Automatic Tensioner
*7 Water Pump Pulley

120 NEW FEATURES – 2GR-FKS ENGINE

2. Automatic Tensioner
The tension of the V-ribbed belt is properly maintained by the tension spring that is enclosed in the automatic
tensioner.

*b
*2

*5

*1 *c

" Text in Illustration A *3
*1 Fulcrum *a *4
*3 Arm
*5 Spring 26L0EG43
*a Cross Section
*c Force of Tensioner *2 Idler Pulley
*4 Bracket
——
*b Force of Belt
——

NEW FEATURES – 2GR-FKS ENGINE 121

JENGINE CONTROL SYSTEM

1. General
The engine control system of the 2GR-FKS engine has the following features.

System Outline
D This is an L-type SFI system. It directly detects the intake air mass
Direct Injection 4-stroke
Gasoline Engine Superior with a hot wire type mass air flow mater sub-assembly.
Version Sequential Multiport D The D-4S SFI system is a fuel injection system which combines direct
Fuel Injection (D-4S SFI)
injection injectors and port injection injectors.
ESA D Based on signals from each sensor, the ECM controls the injection
(Electronic Spark Advance)
volume and timing of each type of injector (direct and port injection
ETCS-i types) in accordance with the engine speed and engine load in order
(Electronic to optimize combustion conditions.
Throttle Control D Ignition timing is determined by the ECM based on signals from
System-intelligent) various sensors. The ECM corrects ignition timing in response to
engine knocking.
VVT-iW D This system selects the optimal ignition timing in accordance with the
(Variable Valve signals received from the sensors and sends (IGT) ignition signals to
Timing-intelligent Wide) the igniters.

VVT-i Optimally controls the opening angle of the throttle valve in accordance
(Variable Valve with the accelerator pedal input and the engine and vehicle conditions.
Timing-intelligent)
Regulates operation of the intake camshaft to ensure an optimal valve
ACIS timing in accordance with the engine condition.
(Acoustic Control
Induction System) Regulates operation of the intake camshaft to ensure an optimal valve
timing in accordance with the engine condition.
Fuel Pump for
Control High-pressure The intake air passages are switched based on engine speed and throttle
Pump valve opening angle to provide high performance in all engine speed
ranges.
for
Low-pressure Regulates the fuel pressure within a range of 2.4 to 20 MPa in
Pump accordance with driving conditions.

Air Conditioning Cut-off D Fuel pump operation is controlled by signals from the fuel pump
Control control ECU.

Air Fuel Ratio D The fuel pump is stopped when an SRS airbag is deployed in a frontal,
Sensor and Oxygen side, or rear side collision.
Sensor Heater Control
By controlling the air compressor with pulley assembly in accordance
with the engine operating conditions, drivability is maintained.
Maintains the temperature of the air fuel ratio sensors or oxygen sensors
at an appropriate level to increase the ability of the sensor to accurately
detect oxygen concentration.

(Continued)

122 NEW FEATURES – 2GR-FKS ENGINE

System Outline

Evaporative Emission D The ECM controls the purge flow of evaporative emissions (HC)
Control from the charcoal canister in accordance with engine operating
conditions.
Engine Immobilizer
Brake Override System D Approximately 5 hours after the ignition switch has been turned OFF,
Fail-Safe the ECM operates the pump module to check for evaporative
Diagnosis emission leakage between the fuel tank and the charcoal canister. The
ECM can detect leaks by monitoring for changes in the fuel tank
pressure.

Prohibits fuel delivery and ignition if an attempt is made to start the
engine with an invalid ignition key.

The driving torque is restricted when both the accelerator and brake
pedals are depressed. (For the Activation Conditions and Inspection
Method, refer to the repair manual.)

When the ECM detects a malfunction, the ECM stops or controls the
engine according to the data already stored in the memory.

When the ECM detects a malfunction, the ECM records the malfunction
and information that relates to the fault.

NEW FEATURES – 2GR-FKS ENGINE 123

2. Construction
The configuration of the engine control system is as shown in the following chart.

Intake Mass Air Flow ECM SFI (for Direct Injection)
Meter Sub-assembly No. 1 Fuel Injector Assembly
Intake Air Temperature Sensor No. 2 Fuel Injector Assembly
No. 3 Fuel Injector Assembly
Crank Position Sensor No. 4 Fuel Injector Assembly
No. 5 Fuel Injector Assembly
VVT Sensors (Intake Camshaft) No. 6 Fuel Injector Assembly

VVT Sensors (Exhaust Camshaft) SFI (for Port Injection)
No. 1 Fuel Injector Assembly
E.F.I. Engine Coolant No. 2 Fuel Injector Assembly
Temperature Sensor No. 3 Fuel Injector Assembly
No. 4 Fuel Injector Assembly
Throttle Position Sensor No. 5 Fuel Injector Assembly
No. 6 Fuel Injector Assembly
Knock Control Sensor
ESA
Stop Light Switch Assembly Ignition Coil Assembly

Power Steering Oil Pressure Spark Plug
Switch
Park/Neutral Position Switch ETCS-i
Assembly* Throttle Control Motor

Transmission Control Switch* VVT-i W (Intake Side)
Cam Timing Oil Control
Ignition or Starter Switch Solenoid Assembly RH
Assembly Cam Timing Oil Control
Solenoid Assembly LH
Accelerator Pedal Rod Assembly
26L0EG118
Cruise Control Main Switch
(Continued)
Fuel Pressure Sensor
(for Low Pressure)

Fuel Pressure Sensor
(for High Pressure)

*: Models with A/T

124 NEW FEATURES – 2GR-FKS ENGINE

Air Fuel Ratio Sensor VVT-i (Exhaust Side)
(Bank 1, Sensor 1)
(Bank 2, Sensor 1) Cam Timing Oil Control
Valve Assembly RH
Oxygen Sensor Cam Timing Oil Control
(Bank 1, Sensor 1) Valve Assembly LH
(Bank 2, Sensor 2)
ACIS
Battery ACIS Actuator

EFI MAIN Relay LIN ECM Fuel Pump Control
Generator Assembly Fuel Pump Control ECU

DLC3 Fuel Pump

CAN Air Fuel Ratio sensor and
(V1 Bus) Oxygen Sensor Heater Control

Air Bag Sensor Assembly Air Fuel Ratio Heater
(Bank 1, Sensor 1)
Transponder Key ECU Assembly* (Bank 2, Sensor 1)

Air conditioner Amplifier Oxygen Sensor Heater
Assembly (Bank 1, Sensor 1)
(Bank 2, Sensor 2)
Combination Meter Assembly
Vehicle Speed Signal Evaporative Emission Control
Canister Pump Module
*: Models with Smart Key System Canister Pressure Sensor
Leak Detection Pump
Vent Valve

No. 1 Vacuum Switching
Valve Assembly

26L0EG119

NEW FEATURES – 2GR-FKS ENGINE 125

3. Layout of Main Components

*5 *6 *7

*4
*3

*2

*1 26L0EG56
*8

" Text in Illustration A *2 Air Fuel Ratio Sensor (Bank 1, Sensor
1)
*1 Purge VSV
*4 Air Fuel Ratio Sensor (Bank 2, Sensor
*3 ECM 1)
*5 Oxygen Sensor (Bank 1, Sensor 2)
*7 Charcoal Canister Assembly *6 Fuel Pump (Low Pressure)
*8 Oxygen Sensor (Bank 2, Sensor 2)

126 NEW FEATURES – 2GR-FKS ENGINE
*4

*1

*2
*3

" Text in Illustration A 26L0EG59

*1 Stop Light Switch Assembly *2 DLC3
*3 Accelerator Pedal Rod Assembly *4 Combination Meter Assembly

NEW FEATURES – 2GR-FKS ENGINE 127

*1 *2
*3 *4
*5

*6

*9
*8

*7

26L0EG57

" Text in Illustration A

Intake Mass Air Flow Meter Throttle Body with Motor Assembly
*1 Sub-assembly *2 D Throttle Position Sensor

D Intake Air Temperature Sensor D Throttle Control Motor

*3 Fuel Injector Assembly (for Port *4 Fuel Injector Assembly (for direct
Injection) injection)

*5 Fuel Pressure Sensor (for Low *6 Fuel Pressure Sensor (for High
Pressure) Pressure)

*7 Crank Position Sensor *8 Cam Timing Oil Control Solenoid
Assembly LH

*9 Cam Timing Oil Control Solenoid ——
Assembly RH

128 NEW FEATURES – 2GR-FKS ENGINE

*4 *5
*3
*2
*1

*6

*9
*7

*8

26L0EG58

" Text in Illustration A *2 Ignition Coil Assembly

*1 VVT Sensor (Bank 2 Intake) *4 VVT Sensor (Bank 1 Intake)
*3 Knock Control Sensor (Bank 1)
*6 Fuel Pump Assembly (for High
*5 VVT Sensor (Bank 1 Exhaust) Pressure)

*7 Engine Coolant Temperature Sensor *8 Knock Control Sensor (Bank 2)
*9 VVT Sensor (Bank 2 Exhaust)
——

NEW FEATURES – 2GR-FKS ENGINE 129

4. Main Components of Engine Control System

General
The main components of the engine control system are as follows:

Components Outline Quantity Function
1
ECM 32-bit CPU The ECM optimally controls the SFI, ESA
1 and ETCS-i to suit the operating
Intake Mass Mass Air Flow Hot-wire Type 1 conditions of the engine in accordance
Air Flow Meter Meter with the signals provided by the sensors.
Sub-assembly Thermistor Type 1
Intake Air 1 This sensor has a built-in silicon chip to
Temperature Thermistor Type 1 directly detect the intake air mass.
Sensor 2
Semiconductor Type (1 each bank) This sensor detects the intake air
E.F.I. Engine Coolant Temperature Pick-up Coil Type temperature by means of an internal
Sensor [36 - 2] 2 thermistor.
Magnetic-Resistance (1 each bank)
Fuel Pressure Sensor Element (MRE) This sensor detects the engine coolant
Type [3] 1 temperature by means of an internal
Crank Position Sensor thermistor.
[No. of Rotor Teeth] Magnetic-Resistance
Element (MRE) The sensor senses the fuel pressure in the
VVT Sensor (Intake Camshaft) Type [3] fuel delivery pipe.
[No. of Rotor Teeth] Linear
(Non-contact) Type This sensor detects the engine speed and
VVT Sensor (Exhaust Camshaft) Linear crankshaft angle.
[No. of Rotor Teeth] (Non-contact) Type
Built-in D This sensor performs cylinder
Accelerator Pedal Sensor Assembly Piezoelectric Type identification.
(Accelerator Pedal Position Sensor) (Non-resonant
Type / Flat Type) D This sensor is used to detect the intake
camshaft position.
Heated Type
(Planar Type) D This sensor performs cylinder
identification.
Heated Type
(Cup Type) D This sensor is used to detect the
exhaust camshaft position.
12-hole Type
This sensor detects the amount of pedal
High Pressure effort applied to the accelerator pedal.
Double Slit Nozzle
Throttle Body Throttle Position Type 1 This sensor detects the throttle valve
with Motor Sensor opening angle.
Assembly

Knock Control Sensor 2 This sensor detects an occurrence of
(Bank 1 and Bank 2) (1 each bank) engine knocking indirectly from the
vibration of the cylinder block caused by
Air Fuel Ratio Sensor 2 the occurrence of engine knocking.
(Bank 1, Sensor 1) (Bank 2, Sensor 1) (1 each bank)
As with the oxygen sensor, this sensor
Oxygen Sensor (Bank 1, Sensor 2) 2 detects the oxygen concentration in the
(Bank 2, Sensor 2) (1 each bank) exhaust gas. However, it detects the
oxygen concentration in the exhaust gas
Fuel Injector for Port injection 6 linearly.
Assembly
for Direct 6 This sensor detects the oxygen
injection concentration in the exhaust gas by
measuring the electromotive force which
is generated in the sensor itself.

The injector is an
electromagnetically-operated nozzle
which injects fuel in accordance with
signals from the ECM.

This injector contains a high-pressure
electromagnetically-operated nozzle to
inject fuel directly into the cylinder.

130 NEW FEATURES – 2GR-FKS ENGINE

Mass Air Flow Meter

D The intake mass air flow meter sub-assembly, which is a slot-in type, allows a portion of the intake air
to flow through the detection area.

D This intake mass air flow meter sub-assembly has built-in intake air temperature sensors.
D Intake air flows past the temperature sensor (before heater), the heater, and then the temperature sensor

(after heater) of the silicon chip sensor in the by-pass duct. As the intake air is warmed up when it is
exposed to the heater, the temperature of the intake air as it flows past the temperature sensor (after heater)
is higher than when it flows past the temperature sensor (before heater). The difference in temperature
of the intake air at each temperature sensor varies depending on the velocity of the intake air that flows
past the silicon chip sensor. The temperature sensor bridge circuit detects the difference in temperature
and the control circuit converts it into a pulse signal and outputs it to the ECM. When the temperature
detected by the temperature sensor (before heater) is higher than that detected by the temperature sensor
(after heater), backflow of the intake air is detected.
D The ECM calculates the intake air volume based on the pulse signal received from the intake mass air
flow meter sub-assembly, and uses it to determine the fuel injection duration necessary for an optimal
air fuel ratio.
D The heater control bridge circuit has a temperature sensor and power transistor, and maintains the heater
temperature at a specific temperature.

Temperature Sensor Temperature Sensor
(before Heater) (after Heater)

Intake Silicon
Air Chip
Sensor
Heater
Intake
Air

5V

Digital Output
Circuit

Heater Control Bridge Circuit Intake Air Volume Detection GND
Bridge Circuit
26L0EG44

NEW FEATURES – 2GR-FKS ENGINE 131

Service Tip

When either of these DTCs is stored, the ECM enters fail-safe mode. During fail-safe mode, the
ECM calculates the fuel injection duration based on the engine speed and throttle valve angle.
Fail-safe mode continues until a pass condition is detected. For details, refer to the Repair Manual.

Crankshaft Position Sensor

The timing rotor of the crankshaft consists of 34 teeth with 2 teeth missing. The crank position sensor
outputs the crankshaft rotation signals every 10_, and the change of the signal due to the missing teeth is
used to determine top-dead-center.

NE Signal Plate (720_ CA)

Engine
Front

Timing Rotor 10_ CA 2 Teeth
Missing
Crank Position
Sensor 26L0EG106

132 NEW FEATURES – 2GR-FKS ENGINE

Intake and Exhaust VVT Sensors

General
Magneto-Resistance Element (MRE) type VVT sensors (intake and exhaust) are used. To detect each
camshaft (intake) position, a timing rotor that is secured to the camshaft (intake) in front of the camshaft
timing gear assembly is used to generate 6 (3 high output, 3 low output) pulses for every 2 revolutions
of the crankshaft. The timing rotor for each camshaft (exhaust) is part of the respective camshaft.

*2

*1

26L0EG107

" Text in Illustration A *2 VVT Sensor
*1 Timing Rotor

" Sensor Output Waveforms A

VVT Sensor Signal Plate (720_ CA)

60_ CA 180_ CA 120_ CA

VVT 180_ CA 60_ CA 120_ CA
Sensor 360_ CA
Signal 360_ CA

0V

Crank
Position
Sensor
Signal

0V

10_ CA 285EG84

NEW FEATURES – 2GR-FKS ENGINE 133

MRE Type VVT Sensor

D An MRE type VVT sensor consists of an MRE, a magnet and a sensor. The direction of the magnetic field
changes due to the profile (protruding and non-protruding portions) of the timing rotor, which passes by
the sensor. As a result, the resistance of the MRE changes, and the output voltage to the ECM changes
to high or low. The ECM detects the camshaft position based on this output voltage.

" Wiring Diagram A

VC ECM
VV1+
VV1–

Timing Rotor VVT Sensor (Bank 1
Intake Side)

Intake VVT Sensor RH 271EG160

" MRE Type and Pick-up Coil Type Output Waveform Image Comparison A

Engine Engine No Detecting
Speed Speed

Sensor Digital Analog Output
Output Output
Sensor
Output

MRE Type Pick-up Coil Type

232CH41

134 NEW FEATURES – 2GR-FKS ENGINE

Accelerator Pedal Position Sensor

This non-contact type accelerator pedal position sensor uses a Hall IC, which is mounted on the accelerator
pedal arm.

D A magnetic yoke is mounted at the base of the accelerator pedal arm. This yoke rotates around the Hall
IC in accordance with the amount of effort that is applied to the accelerator pedal. The Hall IC converts
the changes in the magnetic flux that occur into electrical signals, and outputs them in the form of
accelerator pedal position signals to the ECM.

D The Hall IC contains 2 circuits, one for the main signal, and one for the sub signal. It converts the
accelerator pedal position (angle) into electric signals that have differing characteristics and outputs them
to the ECM.

*1 *3

" Text in Illustration A *2

*1 Hall IC 26L0EG83
*3 Magnetic Yoke
*2 Accelerator Pedal Arm
——

Accelerator Pedal VPA V
Position Sensor EPA 5
VCPA
Magnet VPA2 Output VPA2
EPA2 Voltage
Hall VCP2 ECM
IC 0
Hall VPA
IC

Magnet Fully Fully
Closed Open

Accelerator Pedal Position (Angle)

26L0EG108

Service Tip

The inspection method differs from a conventional accelerator pedal position sensor because this
sensor uses a Hall IC. For details, refer to the Repair Manual.

NEW FEATURES – 2GR-FKS ENGINE 135

Throttle Position Sensor

This non-contact type throttle position sensor uses a Hall IC, which is mounted on the throttle body with
motor assembly.

D The Hall IC is surrounded by a magnetic yoke. The Hall IC converts the changes that occur in the
magnetic flux into electrical signals, and outputs them in the form of throttle valve position signals to
the ECM.

D The Hall IC contains circuits for the main and sub signals. It converts the throttle valve opening angle
into electric signals that have differing characteristics, and outputs them to the ECM.

Magnet
Hall IC

Magnet
Throttle Position Sensor

Magnet Hall IC (V)
5
VTA2
Output
VTA ECM Voltage VTA
E2
VC 0 20 40 60 80
VTA2 Fully Closed Fully Open

Magnet Hall IC

Throttle Position Sensor Throttle Valve Opening Angle

26L0EG84

136 NEW FEATURES – 2GR-FKS ENGINE

Knock Sensor (Flat Type)

1) General

In a conventional type knock control sensor (resonant type), a vibration plate is built into the sensor. This
plate has the same resonance point as the knocking* frequency of the engine block. This sensor can only
detect vibration in this frequency band.
The other type of knock control sensor, a flat type knock control sensor (non-resonant type) has the ability
to detect vibration in a wider frequency band (from about 6 kHz to 15 kHz). It has the following features:

D The engine knocking frequency will vary slightly depending on the engine speed. The flat type knock
sensor can detect vibration even when the engine knocking frequency changes. Due to the use of the
flat type knock control sensor, the vibration detection ability is increased compared to a conventional
type knock control sensor, and more precise ignition timing control is possible.

*: The term “Knock” or “Knocking” is used in this case to describe either preignition or detonation of
the air fuel mixture in the combustion chamber. This preignition or detonation refers to the air fuel
mixture being ignited earlier than is advantageous.
This use of “Knock” or “Knocking” is not primarily used to refer to a loud mechanical noise that may
be produced by an engine.

: Resonance Characteristic of Conventional Type
: Resonance Characteristic of Flat Type

(V) A: Detection Band of
Voltage A Conventional Type

B: Detection Band of
Flat Type

B

Frequency (Hz)

Characteristic of Knock Control Sensor 214CE04

NEW FEATURES – 2GR-FKS ENGINE 137

2) Construction

D A flat type knock control sensor is installed to an engine by placing it over the stud bolt installed on
the cylinder block sub-assembly. For this reason, a hole for the stud bolt exists in the center of the
sensor.

D In the sensor, a steel weight is located in the upper portion. An insulator is located between the weight
and a piezoelectric element.

D An open/short circuit detection resistor is integrated in the sensor.

*1 *4 *3
*2 *5
*3

*a *b

26L0EG110

" Text in Illustration A

*1 Steel Weight *2 Insulator

*3 Piezoelectric Element *4 Open Circuit Detection Resistor

*5 Vibration Plate ——

*a Flat Type Knock Sensor *b Conventional Type Knock Sensor
(Non-Resonant Type) (Resonant Type)

138 NEW FEATURES – 2GR-FKS ENGINE

3) Operation *1 214CE08
*2
Vibrations caused by knocking are *3
transmitted to the steel weight. The inertia of
this weight applies pressure to the *2 Inertia
piezoelectric element. This action generates ——
electromotive force.

" Text in Illustration A

*1 Steel Weight
*3 Piezoelectric Element

4) Open/Short Circuit Detection Resistor

When the ignition is ON, the open/short circuit detection resistor in the knock control sensor and the
resistor in the ECM keep the voltage at terminal KNK1 constant.
An IC (Integrated Circuit) in the ECM constantly monitors the voltage of terminal KNK1. If the
open/short circuit occurs between the knock control sensor and the ECM, the voltage of terminal KNK1
will change and the ECM will detect the open/short circuit and store a DTC (Diagnostic Trouble Code).

ECM

Piezoelectric 5V
Element
KNK1 200 kΩ
Flat Type Knock Control Sensor
IC
200 kΩ

EKNK

Open/Short Circuit 214CE06
Detection Resistor

NEW FEATURES – 2GR-FKS ENGINE 139

Air Fuel Ratio Sensor and Heated Oxygen Sensor

1) General

D A planar type air fuel ratio sensor and a cup type oxygen sensor are used.
D The oxygen sensors are located behind each left and right Three-Way Catalytic converters (TWCs).

The output voltage of the oxygen sensor changes in accordance with the oxygen concentration in the
exhaust gas. The ECM uses this output voltage to determine whether the present air fuel ratio is richer
or leaner than the stoichiometric air fuel ratio.
D The planar type air fuel ratio sensor uses alumina, which excels in heat conductivity and electrical
insulation, to integrate a sensor element with a heater, thus improving the warm-up performance of
the sensor.

*c *d *g
*d *h *e *h

*g *f
*b
*e *f
*a 26L0EG85

" Text in Illustration A

*a Air Fuel Ratio Sensor (Planar Type) *b Oxygen Sensor (Cup Type)

*c Dilation Layer *d Alumina

*e Platinum Electrode *f Sensor Element (Zirconia)

*g Heater *h Atmosphere

140 NEW FEATURES – 2GR-FKS ENGINE

2) Characteristics

As illustrated below, the conventional oxygen sensor is characterized by a sudden change in its output
voltage at the threshold of the stoichiometric air fuel ratio (14.7 : 1). In contrast, the air fuel ratio sensor
data is approximately proportionate to the existing air fuel ratio. The air fuel ratio sensor converts the
oxygen density to current and sends it to the ECM. As a result, the detection precision of the air fuel ratio
has been improved. The air fuel ratio sensor data can only be read using a Techstream.

(V) 4.2 : Air Fuel Ratio Sensor
: Heated Oxygen Sensor

1 (V)

Air Fuel Ratio Sensor Oxygen Sensor
Data Displayed on Output
Hand-held Tester

2.2 0.1
19 (Lean)
11 (Rich) 14.7
Air Fuel Ratio D13N11

*: This calculation value is used internally in ECM and is not an ECM terminal voltage.

NEW FEATURES – 2GR-FKS ENGINE 141

5. SFI (Sequential Multiport Fuel Injection) System

D The D-4S SFI system directly detects the intake air mass with a hot-wire type intake mass air flow meter
sub-assembly.

D The D-4S system is a fuel injection system which combines direct injection injectors and port injection
injectors.

D Based on signals from each sensor, the ECM controls the injection volume and timing of each type of fuel
injector (direct and port injection types) in accordance with engine load and engine speed in order to
optimize combustion conditions.

D To promote warm-up of the catalyst after a cold engine start, this system uses a stratified air fuel mixture.
This creates an area near the spark plug that is richer than the rest of the air fuel mixture. This also allows
a greater amount of ignition timing retard to be used, raising the exhaust gas temperature. The increased
exhaust gas temperatures promote rapid warm-up of the catalysts, significantly reducing exhaust
emissions.

Heavy Direct Injection

Engine Load

Direct Injection
+ Port Injection

Engine Speed High

Fuel Injection System Activation Ranges 26L0EG86

D Stratified Combustion: To achieve stratified combustion, immediately after a cold engine start, fuel is
injected into the intake port from the fuel injector assembly (for port injection) during the exhaust stroke.
Fuel is also injected from the fuel injector assembly (for direct injection) near the end of the compression
stroke. This results in an air fuel mixture that is stratified, and the area near the spark plug is richer than
the rest of the air fuel mixture. This allows a retarded ignition timing to be used, raising the exhaust gas
temperature. The increased exhaust gas temperatures promote rapid warm up of the catalysts, and
significantly improve exhaust emission performance.

142 NEW FEATURES – 2GR-FKS ENGINE

Expansion to Intake Stroke Intake Stroke

Fuel is injected into the intake port from The intake valves open and a
the fuel injector assembly (for port homogeneous air fuel mixture is
injection) before the intake valves open. drawn into the combustion chamber.

Combustion
Mixture Layer

Ignition to Combustion Stroke Compression Stroke

Injected fuel is directed along the piston contour Fuel is injected into the combustion
to the area near the spark plug. This produces a chamber from the fuel injector
com bustible area of rich air fuel mixture that assembly (for direct injection) near
allows for easy ignition. This allows combustion the end of compression stroke.
of a lean air fuel mixture to occur.
26L0EG79

D Homogeneous Combustion: To optimize combustion conditions, the ECM controls injection volume and
timing of the fuel injector assemblies (for port injection) which inject fuel into the intake ports during the
expansion, exhaust, and intake strokes. The ECM also controls the injection volume and timing of the fuel
injector assemblies (for direct injection) which inject fuel during the first half of the intake stroke. The
homogeneous air fuel mixture is created by either combined or individual use of the 2 different types of
injectors. This allows utilization of the evaporation heat of the injected fuel to cool the compressed air,
and it also allows an increase of charging efficiency and power output.

NEW FEATURES – 2GR-FKS ENGINE 143

Expansion to Intake Stroke Intake Stroke

Fuel is injected into the intake port from the The intake valves open to allow the
fuel injector assembly (for port injection) homogeneous air fuel mixture into the
before the intake valves open. combustion chamber, and fuel is injected
into the combustion chamber from the fuel
injector assembly (for direct injection)
during the first half of the intake stroke.

The injected fuel and air are evenly
mixed by intake air force.

Ignition to Combustion Stroke Compression Stroke
The homogeneous air fuel mixture is
The spark plug ignites the homogeneous compressed.
air fuel mixture.
26L0EG80

144 NEW FEATURES – 2GR-FKS ENGINE

6. ESA (Electronic Spark Advance) System

D The Direct Ignition System (DIS) is used. Each ignition coil assembly is equipped with a built-in igniter,
and one ignition coil assembly is provided for each cylinder.

D The ECM assembly calculates the most appropriate ignition timing and the time that current is applied to
the primary windings of the ignition coil based on the signals sent from various sensors. The ECM
assembly then sends an ignition command signal to the igniter of the ignition coil assembly.

D The ignition timing is obtained using the following formula:
Ignition timing = A or B + C
Where: A: Base ignition timing, B: Basic advance, C: Compensation advance

" Ignition Timing Controls A

A. Fixed advance characteristics The base ignition timing is 10_ BTDC. It is fixed at 5_ BTDC while
the engine is starting.
B. Basic advance characteristics
The most appropriate ignition timing is selected from a map based
C. Compensation advance on the signals from a variety of sensors.
characteristics
The ignition timing is advanced or retarded depending on the signals
C-1. Warm engine advance from a variety of sensors.
characteristics
When the engine coolant temperature is low, the ignition timing is
C-2. Idle stabilization advance advanced in accordance with driving conditions to enhance
characteristics drivability.
C-3. Transition compensation
retard If the idle speed drops, the ignition timing is advanced to stabilize the
idle speed. If the idle speed increases, the ignition timing is retarded.
C-4. Retard when accelerating
To prevent knocking, the ignition timing is retarded during sudden
C-5. Knock compensation retard acceleration at a coolant temperature of 60_C (140_F) or more.

The ignition timing is temporarily retarded during acceleration to
enhance drivability.

If knock occurs, the ignition timing is corrected based on the signal
from the knock sensor.

NEW FEATURES – 2GR-FKS ENGINE 145

7. ETCS-i (Electronic Throttle Control System-intelligent)

1) General
With a conventional throttle body, the throttle valve angle is determined invariably by the position of the
accelerator pedal. In contrast, ETCS-i uses the ECM to calculate the optimal throttle valve angle that is
appropriate for the corresponding driving conditions. The ETCS-i throttle uses a throttle control motor
to control the angle.

" System Diagram A

Accelerator Pedal Throttle Valve Throttle Position Sensor
Position Sensor Throttle Control Motor

Intake Mass Flow ECM Ignition Coil Assembly
Meter Sub-assembly
Fuel Injector Assembly
Cruise Control (for Port Injection)
Main Switch Fuel Injector Assembly
(for Direct Injection)
CAN
(V1 Bus) 26L0EG89

Skid Control ECU

146 NEW FEATURES – 2GR-FKS ENGINE

2) Control

a. General
The ETCS-i consists of the following functions:
D Normal Throttle Control (Non-linear Control)
D ISC (Idle Speed Control)
D TRAC (Traction Control)
D VSC (Vehicle Stability Control)
D Cruise Control*
*: Models with cruise control system

b. Normal Throttle Control (non-linear control)
Controls the throttle to an optimal throttle valve angle that is appropriate for the driving condition based
on information such as the amount of the accelerator pedal effort and the engine speed in order to realize
excellent throttle control and comfort in all operating ranges.

" Control Examples During Acceleration and Deceleration A

: With Control
: Without Control

Vehicle’s "
Longitudinal G
0
Throttle Valve "
Opening Angle
0
Ignition Timing "
0
Time !
150EG37

c. Idle Speed Control
The ECM controls the throttle valve in order to constantly maintain an ideal idle speed.

d. TRAC Throttle Control
As part of the TRAC system, the throttle valve is closed by a demand signal from the Skid Control ECU
if an excessive amount of slippage occurs at a drive wheel, thus facilitating excellent vehicle stability
and driving force.

NEW FEATURES – 2GR-FKS ENGINE 147

e. VSC Coordination Control
In order to bring the effectiveness of the VSC system control into full play, the throttle valve angle is
controlled by effecting a coordination control with the Skid Control ECU.

f. Cruise Control
An ECM directly actuates the throttle valve to control engine power for cruise control.

148 NEW FEATURES – 2GR-FKS ENGINE

8. VVT-i (Variable Valve Timing-intelligent) System

1) General

D The VVT-iW (Variable Valve Timing-intelligent Wide) control is designed to control the intake
camshaft within a range of 80_ (of Crankshaft Angle) to provide valve timing optimally suited to the
engine condition. This improves torque in all the speed ranges as well as increasing fuel economy and
reducing exhaust emissions.

D The operation angle for the VVT-iW has been made larger for the retarded side compared to the VVT-i.
During partial load driving, the Atkinson cycle is entered, pumping loss is further reduced and fuel
economy is enhanced.

" VVT-iW System A

Intake Mass Air Flow
Meter Sub-assembly
Intake Air
Temperature Sensor

Crank Position Sensor

VVT Sensor ECM Duty Cycle Cam Timing Oil Control
(Bank 1 Intake Side) Control Solenoid Assembly
(Bank 1 Intake Side)
VVT Sensor Duty Cycle
(Bank 2 Intake Side) Control Cam Timing Oil Control
Solenoid Assembly
Vehicle Speed Signal (Bank 2 Intake Side)

Engine Coolant
Temperature Sensor

Throttle Position
Sensor

Accelerator Pedal
Sensor Assembly

26L0EG90

NEW FEATURES – 2GR-FKS ENGINE 149

D The Variable Valve Timing-intelligent (VVT-i) control is designed to control the exhaust camshaft
within a range of 51_ respectively (of Crankshaft Angle) to provide valve timing optimally suited to
the engine condition. This improves torque in all the speed ranges as well as increasing fuel economy
and reducing exhaust emissions.

" VVT-i System A

Intake Mass Air Flow
Meter Sub-assembly
Intake Air
Temperature Sensor

Crank Position Sensor

VVT Sensor ECM Duty Cycle Cam Timing Oil Control
(Bank 1 Exhaust Side) Control Solenoid Assembly
(Bank 1 Exhaust Side)
VVT Sensor Duty Cycle
(Bank 2 Exhaust Side) Control Cam Timing Oil Control
Solenoid Assembly
Vehicle Speed Signal (Bank 2 Exhaust Side)

Engine Coolant
Temperature Sensor

Throttle Position
Sensor

Accelerator Pedal
Sensor Assembly

26L0EG114

150 NEW FEATURES – 2GR-FKS ENGINE

2) Effectiveness of the VVT-i System
D In order to ensure engine startability, an intermediate lock mechanism is used for the VVT-iW.
D The following effects can be achieved due to the advanced angle and retarded angle of the intake and
exhaust valves.

" Operation Model Diagram: Upon Starting and Idling A

Exhaust Valve Opening Intake Valve Opening
(Advanced Position) (Intermediate Position)

Ensuring Starting Ability 26L0EG91

" Operation Model Diagram: At Partial Load A

Exhaust Valve Opening
(Retarded Position)

Intake Valve Opening
(Retarded Position)

Atkinson Cycle 26L0EG92

" Operation Model Diagram: At Partial Load to Heavy Load A

Exhaust Valve Opening Intake Valve Opening
(Retarded Position) (Advanced Position)

Using Internal EGR or Improving Exhaust Ability 26L0EG93

NEW FEATURES – 2GR-FKS ENGINE 151

D The throttle valve, VVT-iW, and VVT-i are coordinated to optimally control the vehicle while driving
normally. Also, the ECM controls each actuator in accordance with the driver’s intentions during
acceleration to achieve a high torque response.

3) Construction

a. VVT-iW Controller

D The intake side uses a camshaft timing gear assembly with 3 vanes.
D 2 lock pins are used to lock the vane during the intermediate phase of the VVT-iW operation range.
D An assist spring, which assists torque in the advanced direction, is used so that the vane returns to

the intermediate phase in response the intake camshaft (camshaft) torque fluctuations to securely
connect the 2 lock pins. As a result, engine startability is ensured when starting the engine (when
cranking) after the engine was stopped in the retarded operation state.
D An oil control valve is built into the camshaft timing gear bolt, which secures the vane to the intake
camshaft (camshaft). As a result, the controlled oil passage is shortened to improve response
performance and operation at low temperatures. The oil control valve switches the oil passage when
pressed by the cam timing oil control solenoid assembly. Oil passage switching is controlled to
continuously change the intake camshaft (camshaft) phase.
D The oil control valve has a structure which allows independent control of when the 2 lock pins are
connected and released, separate from the advance control and retard control. As a result, a lock
operation can be performed during the intermediate phase of the VVT-iW operation range.

" Intake Side VVT-iW Controller A

*7 *8 *9

*3 *4

*2
*1

*5 *6

26L0EG45

" Text in Illustration A *2 Assist Spring

*1 Camshaft Timing Gear Bolt *4 Vane (Fixed on Intake Camshaft
(Camshaft))
*3 Camshaft Timing Gear Cover FR
*6 Housing
*5 Lock Pin
*7 Timing Gear Cover RR *8 Sprocket
*9 Intake Camshaft (Camshaft)
——

152 NEW FEATURES – 2GR-FKS ENGINE

" Lock Pin A

*1 *c

*2 *d
*a *b

" Text in Illustration A 26L0EG94

*1 Outer Pin *2 Inner Pin
*a Lock Pin Connected *b Lock Pin Released
*c Engine Oil *d Ratchet Groove

" Camshaft Timing Gear Bolt (Built into Oil Control Valve) A

*1 *b *c *d

*a

*a *e 26L0EG47
*d

" Text in Illustration A ——
*b to Advance Side Vane Chamber
*1 Oil Control Valve *d Engine Oil
*a Drain ——
*c to Retard Side Vane Chamber
*e to Lock Pin

b. VVT-i Controller

D The exhaust side uses a camshaft timing exhaust gear assembly with 4 vanes.
D When the engine stops, each camshaft timing exhaust gear assembly is locked at the most advanced

angle. This ensures excellent engine startability.

D The oil pressure sent from the advance or retard side passages of the exhaust camshafts causes
rotation of the vane relative to the timing chain sprocket, to vary the valve timing continuously.

D An advance assist spring is provided on the camshaft timing exhaust gear assembly. This helps to
apply torque in the advance angle direction so that the vane lock pin securely engages with the
housing when the engine stops.

NEW FEATURES – 2GR-FKS ENGINE 153
" Exhaust Side VVT-i Controller A *6

*5
*4

*3
*2

*1

26L0EG46

" Text in Illustration A *2 Camshaft Timing Gear Cover FR
*1 Camshaft Timing Gear Bolt
*3 Housing *4 Vane (Fixed on Intake Camshaft
*5 Camshaft Timing Gear Cover RR (Camshaft))

*6 Exhaust Camshaft (No. 2 Camshaft)

*1 *b *c

*d *a
*a *b *c
26L0EG48
" Text in Illustration A
*1 Oil Control Valve ——
*a Drain *b to Advance Side Vane Chamber
*c to Retard Side Vane Chamber *d Engine Oil

154 NEW FEATURES – 2GR-FKS ENGINE

4) Operation

a. Advance

The cam timing oil control solenoid assembly operates according to the advance signal from the ECM.
When the oil control valve reaches the position shown in the following illustration, the advance side
vane chamber of the VVT-iW controller (camshaft timing gear assembly) is affected by oil pressure and
the vane inside the VVT-iW controller (camshaft timing gear assembly) rotates in the advanced
direction. The intake camshaft (camshaft) fixed to the vane also rotates to the advanced side.

" Intake Side A

*a *b *2

*e

*g

*1

*c *3 *f *d *f 26L0EG49

" Text in Illustration A

*1 Vane *2 ECM

*3 Cam Timing Oil Control Solenoid ——
Assembly
*b Retard Side Vane Chamber
*a Rotation Direction *d to Advance Side Vane Chamber
*f Drain
*c Advance Side Vane Chamber ——

*e from Retard Side Vane Chamber

*g Oil Pressure

NEW FEATURES – 2GR-FKS ENGINE 155

" Exhaust Side A *a *2
*1 *d
*e

*g

*b *c *3 *f

*f 26L0EG51

" Text in Illustration A

*1 Vane *2 ECM

*3 Cam Timing Oil Control Solenoid ——
Assembly
*b Retard Side Vane Chamber
*a Rotation Direction *d to Advance Side Vane Chamber
*f Drain
*c Advance Side Vane Chamber ——

*e from Retard Side Vane Chamber

*g Oil Pressure

156 NEW FEATURES – 2GR-FKS ENGINE

b. Retard
The cam timing oil control solenoid assembly operates according to the retard signal from the ECM.
When the oil control valve reaches the position shown in the following illustration, the retard side vane
chamber of the VVT-iW controller (camshaft timing gear assembly) is affected by oil pressure and the
vane inside the VVT-iW controller (camshaft timing gear assembly) rotates in the retarded direction.
The intake camshaft (camshaft) fixed to the vane also rotates to the retarded side.

" Intake Side A

*2
*a *d *e

*1 *c *3 *f *g
*b
26L0EG50

" Text in Illustration A

*1 Vane *2 ECM

*3 Cam Timing Oil Control Solenoid ——
Assembly
*b Retard Side Vane Chamber
*a Rotation Direction *d from Retard Side Vane Chamber
*f Drain
*c Advance Side Vane Chamber ——

*e to Retard Side Vane Chamber

*g Oil Pressure

NEW FEATURES – 2GR-FKS ENGINE 157

" Exhaust Side A *2 *e
*d
*a
*1

*g

*b *3 *f
*c 26L0EG52

" Text in Illustration A *2 ECM
——
*1 Vane *b Retard Side Vane Chamber
*d from Retard Side Vane Chamber
*3 Cam Timing Oil Control Solenoid *f Drain
Assembly ——

*a Rotation Direction

*c Advance Side Vane Chamber

*e to Retard Side Vane Chamber

*g Oil Pressure

c. Hold

The ECM calculates the target advanced angle according to driving conditions and performs control.
After setting the target timing, timings are maintained by the neutral oil control valve as long as driving
conditions do not change. As a result, unnecessary engine oil discharge is suppressed while valve
timings are aligned to the desired target position.

158 NEW FEATURES – 2GR-FKS ENGINE

9. ACIS (Acoustic Control Induction System)

1) General

The Acoustic Control Induction System (ACIS) uses a bulkhead to divide the intake manifold, creating
2 stages. The intake air control valve in the bulkhead is opened or closed to vary the effective length of
the intake manifold in accordance with the engine speed and throttle valve opening angle. This increases
the power output in all ranges from low to high speed.

" System Diagram A

Crankshaft Throttle Opening Angle
Position Sensor

Throttle Valve

ECM

ACIS Actuator Intake Air Control Valve

285EG58

2) Construction

a. Intake Air Control Valve
The intake air control valve is installed in the intake air chamber. It opens and closes to provide two
effective lengths of the intake manifold.

b. ACIS Actuator (Motor)
The ACIS actuator activates the intake air control valve based on signals from the ECM.

*1

*2 26L0EG53

" Text in Illustration A *2 ACIS Actuator
*1 Intake Air Control Valve

NEW FEATURES – 2GR-FKS ENGINE 159

3) Operation

a. Intake Control Valve Closed

While the engine is running at low or medium speed under high load, the ECM causes the actuator to
close the control valve. As a result, the effective length of the intake manifold is lengthened and the
intake efficiency, in the low or medium speed range, is improved due to the dynamic effect (inertia) of
the intake air, thereby increasing power output.

When the intake air control valve closes: Control Valve Closed
Intake Air Control Valve (Closed)
Throttle Valve Wide

Torque

Narrow High
Low
26L0EG115
: Effective Intake Manifold Length Engine Speed

b. Intake Control Valve Open

Under any condition except when the engine is running at low or medium speed under high load, the
ECM causes the actuator to open the control valve. When the control valve is open, the effective length
of the intake air chamber is shortened and peak intake efficiency is shifted to the high engine speed
range, thus providing greater output at high engine speeds.

When the intake air control valve opens:

Intake Air Control Valve (Open) Control Valve Open
Throttle Valve Wide

Torque

: Effective Intake Manifold Length Narrow

: Effective Intake Air Surge Tank Length Low High
Engine Speed

26L0EG116

160 NEW FEATURES – 2GR-FKS ENGINE

10. Fuel Pump Control

D The fuel pump control ECU receives an operation request signal (duty signal) from the ECM and operates
the fuel pump.

D Three-phase Pulse Width Modulation (PWM) control is used for the fuel pump control ECU to steplessly
adjust the rotation of the fuel pump speed. Due to this control, the fuel pump can be operated at the optimal
speed for the required fuel flow, reducing power consumption and improving fuel efficiency.

D In addition to when the engine is stopped, the fuel pump is stopped when any of the Supplemental Restraint
System (SRS) airbags have deployed, minimizing fuel leakage.

EFI MAIN
Relay

from each CAN ECM Fuel Pump Fuel
Airbag Control Pump
Sensor Airbag (V1 Bus) ECU
Sensor
Assembly

26L0EG95

NEW FEATURES – 2GR-FKS ENGINE 161

11. Evaporative Emission Control System

1) General

D The evaporative emission control system prevents the fuel vapor that is created in the fuel tank
assembly from being released directly into the atmosphere.

D The canister stores the fuel vapor that has been created in the fuel tank assembly.
D This system consists of a purge VSV, canister, canister pump module and ECM.
D The ECM controls the purge VSV in accordance with the driving conditions in order to direct the fuel

vapor into the engine, where it is burned.
D In this system, the ECM checks for evaporative emission leaks and stores Diagnostic Trouble Codes

(DTCs) in the event of a malfunction. An evaporative emission leak check consists of an application
of vacuum to the evaporative emission system and the ECM monitoring the system for changes in
pressure in order to detect a leak.
D The Onboard Refueling Vapor Recovery (ORVR) system is used.
D The canister pressure sensor is included in the canister pump module.
D A canister filter is provided on the fresh air line. This canister filter is maintenance-free.
D The following are the typical conditions necessary to enable an evaporative emission leak check:

Typical Enabling Condition D 5 hours have elapsed after the engine has been turned OFF*.
D Altitude: Below 2400 m (8000 feet)
D Battery Voltage: 10.5 V or more
D Ignition Switch: OFF
D Engine Coolant Temperature: 4.4 to 35_C (40 to 95_F)
D Intake Air Temperature: 4.4 to 35_C (40 to 95_F)

*: If engine coolant temperature does not drop below 35_C (95_F), this time should be extended to 7
hours. Even after that, if the temperature is not less than 35_C (95_F), the time should be extended
to 9.5 hours.

Service Tip

The pump module performs a fuel evaporative emission leakage check. This check is done
approximately 5 hours after the engine is turned off. Sound may be heard coming from
underneath the luggage compartment for several minutes. This does not indicate a malfunction.
D Pinpoint pressure test procedure is adopted by pressurizing the fresh air line that runs from the

pump module to the air filler neck. For details, see the Repair Manual.

162 NEW FEATURES – 2GR-FKS ENGINE

2) System Diagram
" Evaporative Emission Control System A

to Intake Manifold Roll-over Valve
Purge VSV Cut-off Valve

Fuel Tank Assembly Vent Valve
Purge Air Line
Fresh Air
Line Canister Filter

ECM Leak Detection Pump
and Pump Motor
Canister Pressure Charcoal
Sensor Canister
Assembly

Canister Pump Module

Reference Orifice
0.02 in. Diameter

26L0EG105

NEW FEATURES – 2GR-FKS ENGINE 163
*5
3) Layout of Main Components

*6

*1

*2 *4
*3
" Text in Illustration A
26L0EG54
*1 Purge Air Line
*2 Fuel Tank Assembly
*3 Canister Filter *4 Fresh Air Line
*6 Charcoal Canister Assembly
Pump Module
——
*5 D Canister Vent Valve
D Vacuum Pump

D Pressure Sensor

Front

26L0EG96

4) Function of Main Components

Component Function
Charcoal Canister
Contains activated charcoal to absorb the fuel vapor that is created in the fuel
Fresh Air Line tank assembly.

Pump Canister Vent Valve Fresh air goes into the charcoal canister and the cleaned drain air goes out
Module Vacuum Pump and into the atmosphere.
Pump Motor
Opens and closes the fresh air line in accordance with signals from the ECM.
Pressure Sensor
Applies vacuum pressure to the evaporative emission system in accordance
EVAP Valve with signals from the ECM.
Canister Filter
ECM Detects the pressure in the evaporative emission system and sends the
signals to the ECM.

Opens in accordance with the signals from the ECM when the system is
purging, in order to send the fuel vapor that was absorbed by the charcoal
canister into the intake manifold. In system monitoring mode, this valve
controls the introduction of vacuum into the fuel tank.

Prevents dust and debris in the fresh air from entering the system.

Controls the pump module and the EVAP valve in accordance with the
signals from various sensors, in order to achieve a purge volume that suits
the driving conditions. In addition, the ECM monitors the system for any
leakage and stores a DTC if a malfunction is found.

164 NEW FEATURES – 2GR-FKS ENGINE

5) Construction and Operation
a. Fuel Inlet (Fresh Air Inlet)
In accordance with the change of structure of the evaporative emission control system, the location of
the fresh air line inlet has been moved from the air cleaner to the near the fuel inlet. The fresh air from
the atmosphere and drain air cleaned by the charcoal canister will go in or out of the system through
the passages shown below.
*1

*3

*2

" Text in Illustration A *a 26L0EG81

*1 Fuel Cap *2 Canister Filter
*3 Fuel Inlet Pipe ——
*a to Canister ——

Fresh Air Cleaned Drain Air

26L0EG96 26L0EG117

NEW FEATURES – 2GR-FKS ENGINE 165

b. Pump Module

D The canister pump module consists of the vent valve, reference orifice, canister pressure sensor, leak
detection pump and pump motor.

D The vent valve switches the passages in accordance with the signals received from the ECM.
D A DC type brushless motor is used for the pump motor.
D A vane type leak detection pump is used.

Fresh Air Canister Pressure Fresh Air
Sensor Vent Valve

Pump Motor

Leak Detection
Pump

Reference
Orifice

Simplified Diagram: Canister Pump Module Canister

Vent Valve (OFF)
Filter

Fresh Air

Leak Detection Pump Filter to Canister
and Pump Motor
26L0EG55
Canister Pressure
Sensor

Reference Orifice [0.5 mm (0.020 in.) Diameter]

166 NEW FEATURES – 2GR-FKS ENGINE

6) System Operation

a. Purge Flow Control

D When the engine has reached a predetermined state [closed loop, engine coolant temperature above
70_C (158_F), etc.], stored fuel vapor is purged from the canister whenever the purge VSV is opened
by the ECM.

D The ECM will change the duty ratio cycle of the purge VSV, thus controlling purge flow volume.
Purge flow volume is determined by intake manifold pressure and the duty ratio cycle of the purge
VSV. Atmospheric pressure is allowed into the canister to ensure that purge flow is constantly
maintained whenever purge vacuum is applied to the canister.

to Intake Atmosphere Charcoal Canister
Manifold Assembly

Purge VSV
(Open)

ECM

26L0EG97

b. ORVR (Onboard Refueling Vapor Recovery)

When the internal pressure of the fuel tank assembly increases during refueling, the fuel vapor enters
the canister. The air that has had the fuel vapor removed from it will be discharged through the fresh
air line. The vent valve is used to open and close the fresh air line. The valve is always open (even when
the engine is stopped) except when the vehicle is in monitoring mode (the valve will remain open as
long as the vehicle is not in monitoring mode). If the vehicle is refueled in system monitoring mode,
the ECM will recognize the refueling by way of the canister pressure sensor, which will detect the
sudden pressure increase in the fuel tank assembly, and the ECM will open the vent valve.

Purge VSV Charcoal Canister
(Close) Assembly

Vent Valve

26L0EG98

NEW FEATURES – 2GR-FKS ENGINE 167

c. EVAP Leak Check
General
The EVAP leak check operates in accordance with the following timing chart:
" Timing Chart A

On (Open)
Purge VSV

Off (Closed)

Vent Valve On
Off (Vent)

On
Leak Detection Pump

Off

Atmospheric Pressure 2) 3) 4) 5) 6)
System Pressure
First Reference Pressure 26L0EG99

1)

168 NEW FEATURES – 2GR-FKS ENGINE

Order Operation Description Time
60 sec.
Atmospheric Pressure The ECM turns the vent valve off (vent) 360 sec.
1) Measurement and measures EVAP system pressure to
determine the atmospheric pressure. Within
First Reference 15 min.
2) Pressure Measurement The leak detection pump creates negative
pressure (vacuum), limited by a reference 10 sec.
3) EVAP Leak Check orifice and the pressure is measured. The 60 sec.
ECM determines this as the reference
4) Purge VSV Monitor pressure. —
Second Reference
The leak detection pump creates negative
5) Pressure Measurement pressure (vacuum) in the EVAP system and
6) Final Check the EVAP system pressure is measured. If
the stabilized pressure is larger than the
reference pressure, ECM determines that
the EVAP system has a leak. If the EVAP
pressure does not stabilize within 15
minutes, the ECM cancels the EVAP
monitor.

The ECM opens the purge VSV and
measures the EVAP pressure increase. If
the increase is large, the ECM interprets
this as normal.

The leak detection pump creates negative
pressure (vacuum) limited by a reference
orifice and the pressure is measured. The
ECM determines this as the reference
pressure.

The ECM measures the atmospheric
pressure and records the monitor result.