Toyota FJ Cruiser (GSJ 10, 15 series). Instruction - part 48

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

ES–147

ES

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

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.

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

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

ES–148

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

ES

•

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:
•

If other DTCs relating to different systems that have terminal E2 as the ground terminal are output 
simultaneously, terminal E2 may have an open circuit.

•

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.

•

If the OX1B wire from the ECM connector is short-circuited to the +B wire, DTC P0136 will be set.

•

If the OX2B wire from the ECM connector is short-circuited to the +B wire, DTC P0156 will be set.

(a) Connect an intelligent tester to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
(c) Select the following menu items: DIAGNOSIS / 

ENHANCED OBD II / DTC INFO / CURRENT CODES.

(d) Read DTCs.

Result

B

C

A

(a) Connect an intelligent tester to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
(c) Select the following menu items: DIAGNOSIS / 

ENHANCED OBD II / DATA LIST / PRIMARY / O2S 
B1S2 or O2S B2S2.

(d) Allow the engine to idle.

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

READ OUTPUT DTCS

Case

A/F Sensor (Sensor 1)

Output Voltage

HO2 Sensor (Sensor 2)

Output Voltage

Main Suspected

Trouble Areas

Display (DTC Output)

Proceed To

P0138 or P0158

A

P0137 or P0157

B

P0136 or P0156

C

              Go to step 14

              Go to step 7

2

READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF HEATED OXYGEN 
SENSOR)

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

ES–149

ES

(e) Read the Heated Oxygen (HO2) sensor output voltage 

while idling.

Result

B

A

(a) Turn the ignition switch OFF and wait for 5 minutes.
(b) Disconnect the B1 or B2 ECM connector.
(c) Check the resistance.

Standard Resistance

(d) Reconnect the ECM connector.

NG

OK

(a) Disconnect the B34 or B36 HO2 sensor connector.
(b) Check the resistance.

Standard Resistance

(c) Reconnect the HO2 sensor connector.

NG

OK

HO2 Sensor Output Voltages

Proceed To

More than 1.2 V

A

Less than 1.0 V

B

              Go to step 5

3

CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT)

B1

ECM Connector

B2

HT1B

OX1B

HT2B

OX2B

G035620E11

Tester Connections

Specified Conditions

HT1B (B1-1) - OX1B (B1-18)

10 k

Ω or higher

HT2B (B2-5) - OX2B (B2-33)

              Go to step 4

REPLACE ECM (See page 

ES-446

)

4

INSPECT HEATED OXYGEN SENSOR (CHECK FOR SHORT)

Component Side:

HO2 Sensor

+B

OX1B or 
OX2B

B36

1

2

3

4

Bank 2

Bank 1

E2

B34

Front View

A062378E38

Tester Connections

Specified Conditions

+B (2) - E2 (4)

10 k

Ω or higher

+B (2) - OX1B or OX2B (3)

REPLACE HEATED OXYGEN SENSOR (See 
page 

EC-24

)

REPAIR OR REPLACE HARNESS OR CONNECTOR

ES–150

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

ES

NEXT

(a) Connect an intelligent tester to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
(c) Select the following menu items: DIAGNOSIS / 

ENHANCED OBD II / DTC INFO / CURRENT CODES.

(d) Read DTCs.

Result

B

A

(a) Connect an intelligent tester to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
(c) Start the engine.
(d) Select the following menu items: DIAGNOSIS / 

ENHANCED OBD II / DATA LIST / PRIMARY / O2S 
B1S2 or O2S B2S2.

(e) After warming up the engine, run the engine at an engine 

speed of 2,500 rpm for 3 minutes.

(f)

Read the output voltage of the HO2 sensor when the 
engine rpm is suddenly increased.
HINT:
Quickly accelerate the engine to 4,000 rpm 3 times using 
the accelerator pedal.
Standard:

Fluctuates between 0.4 V or less and 0.5 V or more.

NG

OK

5

PERFORM CONFIRMATION DRIVING PATTERN

6

CHECK WHETHER DTC OUTPUT RECURS (DTC P0138 OR P0158)

Display (DTC Output)

Proceed To

P0138 or P0158

A

No output

B

CHECK FOR INTERMITTENT PROBLEMS

REPLACE HEATED OXYGEN SENSOR (See page 

EC-24

)

7

READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF HEATED OXYGEN 
SENSOR)

              Go to step 14