Toyota Tundra. Manual — part 1180

c. Warm up the engine.

d. Enter the following menus: Powertrain/Engine and ECT/Active Test/Control the Injection Volume

for A/F sensor.

e. Change the fuel injection volume using the Techstream, monitoring the voltage output of Air Fuel

Ratio (A/F) and HO2 sensors displayed on the Techstream.

HINT:



Change the fuel injection volume within the range of -12% and +12%. The injection volume
can be changed in 1% graduations within the range.



The A/F sensor is displayed as AFS B1S1 or AFS B2S1, and the HO2 sensor is displayed as
O2S B1S2 or O2S B2S2, on the Techstream.

Result

RESULT CHART

HINT:

A normal HO2 sensor voltage (O2S B1S2 or O2S B2S2) reacts in accordance with increases and
decreases in fuel injection volumes. When the A/F sensor voltage remains at either less or more
than 3.3 V despite the HO2 sensor indicating a normal reaction, the A/F sensor is malfunctioning.

Tester Display (Sensor)

Voltage Variation

Proceed To

AFS B1S1 (A/F)
AFS B2S1 (A/F)

Alternates between more and less than 3.3 V

OK

AFS B1S1 (A/F)
AFS B2S1 (A/F)

Remains at more than 3.3 V

NG

AFS B1S1 (A/F)
AFS B2S1 (A/F)

Remains at less than 3.3 V

NG

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

Fig. 88: A/F & HO2 Sensor Output Voltage Graph

NG : Go to step 14

OK : CHECK AND REPAIR EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO
(FUEL INJECTOR ASSEMBLY, FUEL PRESSURE, GAS LEAK FROM SYSTEM, ETC.)

8. CHECK EXHAUST GAS LEAK

OK: No gas leakage.

NG : REPAIR OR REPLACE EXHAUST GAS LEAKAGE POINT (See ON-VEHICLE
INSPECTION ).

OK : Go to next step

9. INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE) . (See INSPECTION

PROCEDURE).

NG : REPLACE HEATED OXYGEN SENSOR (See REMOVAL )

OK : Go to next step

10. CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - ECM)

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

OK : Go to next step

11. REPLACE HEATED OXYGEN SENSOR

a. Replace the heated oxygen sensor (See REMOVAL ).

12. PERFORM CONFIRMATION DRIVING PATTERN

13. CHECK WHETHER DTC OUTPUT RECURS (DTC P0136, P0137, P0138, P0156, P0157 OR

P0158)

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch ON.

c. Turn the Techstream ON.

d. Enter the following menus: Powertrain/Engine and ECT/Utility/All Readiness.

e. Input DTCs: P0136, P0137, P0138, P0156, P0157 and P0158.

f. Check the DTC monitor is NORMAL. If DTC monitor is INCOMPLETE, perform the drive

pattern adding the vehicle speed and using the second gear to decelerate the vehicle.

Result

RESULT CHART

B : REPLACE AIR FUEL RATIO SENSOR (See REMOVAL )

A : END

14. REPLACE AIR FUEL RATIO SENSOR

a. Replace the air fuel ratio sensor (See REMOVAL ).

15. PERFORM CONFIRMATION DRIVING PATTERN

16. CHECK WHETHER DTC OUTPUT RECURS (DTC P0136, P0137, P0138, P0156, P0157 OR

P0158)

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch ON.

c. Turn the Techstream ON.

d. Enter the following menus: Powertrain/Engine and ECT/Utility/All Readiness.

e. Input DTCs: P0136, P0137, P0138, P0156, P0157 and P0158.

f. Check the DTC monitor is NORMAL. If DTC monitor is INCOMPLETE, perform the drive

pattern adding the vehicle speed and using the second gear to decelerate the vehicle.

Result

RESULT CHART

Display (DTC Output)

Proceed To

NORMAL (No DTC output)

A

INCOMPLETE (P0136, P0137, P0138, P0156, P0157 or P0158 detected)

B

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

B : REPLACE HEATED OXYGEN SENSOR (See REMOVAL )

A : END

17. READ VALUE USING TECHSTREAM (OUTPUT VOLTAGE OF HEATED OXYGEN

SENSOR)

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch ON.

c. Turn the Techstream ON.

d. Enter the following menus: Powertrain/Engine and ECT/Data List/A/F Control System/O2S B1 S2

or O2S B2 S2.

e. After warming up the engine, run the engine at an engine speed of 2500 RPM for 3 minutes.

f. Engine is idling.

g. Depress the accelerator pedal quickly until the engine speed reaches 2500 RPM 3 times.

Result

RESULT CHART

B : Go to step 20

A : Go to next step

18. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT)

a. Turn the ignition switch OFF and wait for 5 minutes.

b. Disconnect the C53 ECM connector.

c. Measure the resistance according to the value(s) in the table below.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

NG : Go to step 19

Display (DTC Output)

Proceed To

NORMAL (No DTC output)

A

INCOMPLETE (P0136, P0137, P0138, P0156, P0157 or P0158 detected)

B

Display (DTC Output) Proceed To

Higher than 1.2 V

A

Below 1.0 V

B

Tester Connection

Condition Specified Condition

D74-45 (HT1B) - D74-114 (OX1B) Always

10 kohms or higher

D74-44 (HT2B) - D74-112 (OX2B) Always

10 kohms or higher

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra