Toyota FJ Cruiser (GSJ 10, 15 series). Instruction - part 94

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

ES–331

ES

Others:

TYPICAL MALFUNCTION THRESHOLDS

P2238 and P2241 (Open circuit between AF+ and AF-):

P2238 and P2241 (Short circuit between AF+ and GND):

P2238 and P2241 (Short circuit between AF+ and AF-):

P2239 and P2242 (Short circuit between AF+ and +B):

P2252 and P2255 (Short circuit between AF- and GND):

P2253 and P2256 (Short circuit between AF- and +B):

WIRING DIAGRAM

Refer to DTC P2195 (See page 

ES-312

).

INSPECTION PROCEDURE

HINT:
Intelligent tester only:
Malfunctioning areas can be identified by performing the A/F CONTROL function provided in the ACTIVE 
TEST. The A/F CONTROL function can help to determine whether the Air-Fuel Ratio (A/F) sensor, Heated 
Oxygen (HO2) sensor and other potential trouble areas are malfunctioning.
The following instructions describe how to conduct the A/F CONTROL operation using an intelligent 
tester.
(1) Connect an intelligent tester to the DLC3.
(2) Start the engine and turn the tester ON.
(3) Warm up the engine at an engine speed of 2,500 rpm for approximately 90 seconds.
(4) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL.
(5) Perform the A/F CONTROL operation with the engine in an idling condition (press the RIGHT or LEFT 
button to change the fuel injection volume).
(6) Monitor the voltage outputs of the A/F and HO2 sensors (AFS B1S1 and O2S B1S2 or AFS B2S1 and 
O2S B2S2) displayed on the tester.
HINT:
•

The A/F CONTROL operation lowers the fuel injection volume by 12.5 % or increases the injection 
volume by 25 %.

•

Each sensor reacts in accordance with increases and decreases in the fuel injection volume.

Standard

Battery voltage

11 V or more

Ignition switch

ON

Time after ignition switch is OFF to ON

5 seconds or more

A/F sensor admittance

Below 0.022 1/

Ω

AF+ terminal voltage

0.5 V or less

Difference between AF+ and AF- terminal voltages

0.1 V or less

AF+ terminal voltage

More than 4.5 V

AF- terminal voltage

0.5 V or less

AF- terminal voltage

More than 4.5 V

Tester Display

(Sensor)

Injection Volumes

Status

Voltages

AFS B1S1 or AFS B2S1

(A/F)

+25 %

Rich

Less than 3.0

AFS B1S1 or AFS B2S1

(A/F)

-12.5 %

Lean

More than 3.35

ES–332

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

ES

NOTICE:
The Air-Fuel Ratio (A/F) sensor has an output delay of a few seconds and the Heated Oxygen 
(HO2) sensor has a maximum output delay of approximately 20 seconds.

•

Following the A/F CONTROL procedure enables technicians to check and graph the voltage outputs of 
both the A/F and HO2 sensors.

•

To display the graph, select the following menu items on the tester: DIAGNOSIS / ENHANCED OBD II 
/ ACTIVE TEST / A/F CONTROL / USER DATA / AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S 
B2S2, and press the YES button and then the ENTER button followed by the F4 button.

HINT:
Read freeze frame data using an intelligent tester. Freeze frame data record the engine condition when 
malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was 
moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other 
data, from the time the malfunction occurred.

NG

O2S B1S2 or O2S B2S2

(HO2)

+25 %

Rich

More than 0.55

O2S B1S2 or O2S B2S2

(HO2)

-12.5 %

Lean

Less than 0.4

Case

A/F Sensor (Sensor 1)

Output Voltage

HO2 Sensor (Sensor 2)

Output Voltage

Main Suspected 

Trouble Areas

1

Injection volume

+25 %

-12.5 %

Injection volume

+25 %

-12.5 %

-

Output voltage

More than 3.35 V

Less than 3.0 V

Output voltage

More than 0.55 V

Less than 0.4 V

2

Injection volume

+25 %

-12.5 %

Injection volume

+25 %

-12.5 %

•

A/F sensor

•

A/F sensor heater

•

A/F sensor circuit

Output voltage

Almost 

no reaction

Output voltage

More than 0.55 V

Less than 0.4 V

3

Injection volume

+25 %

-12.5 %

Injection volume

+25 %

-12.5 %

•

HO2 sensor

•

HO2 sensor heater

•

HO2 sensor circuit

Output voltage

More than 3.35 V

Less than 3.0 V

Output voltage

Almost 

no reaction

4

Injection volume

+25 %

-12.5 %

Injection volume

+25 %

-12.5 %

•

Injector

•

Fuel pressure

•

Gas leakage from 
exhaust system

(Air-fuel ratio extremely 
lean or rich)

Output voltage

Almost 

no reaction

Output voltage

Almost 

no reaction

1 

INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) (See page 

ES-85

)

Tester Display

(Sensor)

Injection Volumes

Status

Voltages

REPLACE AIR FUEL RATIO SENSOR

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

ES–333

ES

OK

NG

OK

NG

OK

Replace the air fuel ratio sensor (See page 

EC-21

).

NEXT

(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
(c) Clear DTCs (See page 

ES-38

).

(d) Start the engine.
(e) Allow the engine to idle for 5 minutes or more.
(f)

Select the following menu items: DIAGNOSIS / 
ENHANCED OBD II / DTC INFO / PENDING CODES.

(g) Read pending DTCs.

Result

B

A

2 

INSPECT AIR FUEL RATIO SENSOR HEATER RELAY (See page 

ES-86

)

REPLACE AIR FUEL RATIO SENSOR 
HEATER RELAY

3 

CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM) (See page 

ES-325

)

REPAIR OR REPLACE HARNESS OR 
CONNECTOR

4

REPLACE AIR FUEL RATIO SENSOR

5

CHECK WHETHER DTC OUTPUT RECURS (DTC P2238, P2239, P2252 OR P2253)

Display (DTC Output)

Proceed To

No output

A

P2238, P2239, P2252 or P2253

B

REPLACE ECM (See page 

ES-446

)

END

ES–334

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

ES

DTC SUMMARY

HINT:
The leak detection pump is built into the canister pump module.

DESCRIPTION

The description can be found in the EVAP (Evaporative Emission) System (See page 

ES-352

).

INSPECTION PROCEDURE

Refer to the EVAP System (See page 

ES-357

).

MONITOR DESCRIPTION

5 hours

*

 after the ignition switch is turned to OFF, the leak detection pump creates negative pressure 

(vacuum) in the EVAP system. The ECM monitors for leaks and actuator malfunctions based on the EVAP 
pressure.
HINT:

*

: If the engine coolant temperature is not below 35

°C (95°F) 5 hours after the ignition switch is turned to 

OFF, the monitor check starts 2 hours later. If it is still not below 35

°C (95°F) 7 hours after the ignition 

switch is turned to OFF, the monitor check starts 2.5 hours later.

DTC

P2401

Evaporative Emission Leak Detection Pump 
Stuck OFF

DTC

P2402

Evaporative Emission Leak Detection Pump 
Stuck ON

DTCs

Monitoring Items

Malfunction Detection Conditions

Trouble Areas

Detection 

Timings

Detection 

Logic

P2401

Leak detection pump 
stuck OFF

P043E, P043F, P2401, P2402 and 
P2419 present when one of following 
conditions met during key-off EVAP 
monitor:
•

EVAP pressure just after reference 
pressure measurement greater than 
-1 kPa-g (-7.5 mmHg-g)

•

Reference pressure less than -4.85 
kPa-g (-36.4 mmHg-g)

•

Reference pressure greater than -
1.057 kPa-g (-7.93 mmHg-g)

•

Reference pressure not saturated

•

Reference pressure difference 
between first and second 0.7 kPa-g 
(5.25 mmHg-g) or more

HINT:
Typical example values

•

Canister pump module 
(Reference orifice, leak 
detection pump, vent 
valve)

•

Connector/wire harness 
(Canister pump module - 
ECM)

•

EVAP system hose (pipe 
from air inlet port to 
canister pump module, 
canister filter, fuel tank 
vent hose)

•

ECM

While ignition 
switch OFF

2 trip

P2402

Leak detection pump 
stuck ON

•

Canister pump module 
(Reference orifice, leak 
detection pump, vent 
valve)

•

Connector/wire harness 
(Canister pump module - 
ECM)

•

EVAP system hose (pipe 
from air inlet port to 
canister pump module, 
canister filter, fuel tank 
vent hose)

•

ECM

While ignition 
switch OFF

2 trip

Sequ

ence

Operations

Descriptions

Duration

-

ECM activation

Activated by soak timer, 5 hours (7 or 9.5 hours) after ignition switch turned to OFF.

-