Toyota Tundra. Manual — part 1178

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

COMPONENT OPERATING RANGE

MONITOR RESULT

Refer to CHECKING MONITOR STATUS .

WIRING DIAGRAM

Fig. 83: Heated Oxygen Sensor Wiring Diagram

CONFIRMATION DRIVING PATTERN

HINT:

Duration until rear heated oxygen sensor voltage drops to 0.2 V during fuel cut

9 seconds or more

Duration of following condition

30 seconds or more

Heated oxygen sensor voltage

Varies between 0.1 V and 0.9 V

2008 Toyota Tundra

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



This confirmation driving pattern is used in the "PERFORM CONFIRMATION DRIVING PATTERN"
procedure of the following diagnostic troubleshooting procedure.



Performing this confirmation driving pattern will activate the Heated Oxygen (HO2) sensor monitor. (The
catalyst monitor is performed simultaneously.) This is very useful for verifying the completion of a
repair.

Fig. 84: Diagnostic Troubleshooting Procedure For Confirmation Driving Pattern

1. Connect the Techstream to the DLC3.

2. Turn the ignition switch ON.

3. Warm up the engine until the engine coolant temperature reaches 75°C (167°F) or more [A].

4. Drive the vehicle at 40 to 75 mph (60 to 120 km/h) for 10 minutes or more [B].

5. Drive the vehicle 40 mph (60 km/h) or more and decelerate the vehicle for 5 seconds or more. Perform

this 3 times [C].

6. Turn the Techstream ON.

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

8. Input DTCs: P0136, P0137, P0138, P0139, P0156, P0157, P0158 and P0159.

9. Check the DTC monitor is NORMAL. If DTC monitor is INCOMPLETE, perform the drive pattern [C]

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

INSPECTION PROCEDURE

HINT:

Malfunctioning areas can be identified by performing the Control the Injection Volume for A/F sensor function
provided in the Active Test. The Control the Injection Volume for A/F sensor 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 Control the Injection Volume for A/F sensor operation
using the Techstream.

2008 Toyota Tundra

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

1. Connect the Techstream to the DLC3.

2. Start the engine and turn the Techstream ON.

3. Warm up the engine at an engine speed of 2500 RPM for approximately 90 seconds.

4. On the Techstream, enter the following menus: Powertrain/Engine and ECT/Active Test/Control the

Injection Volume for A/F sensor.

5. Perform the Active Test operation with the engine in an idling condition (press the RIGHT or LEFT

button to change the fuel injection volume).

6. Monitor the output voltages of the A/F and HO2 sensors (AFS B1 S1 and O2S B1 S2 or AFS B2 S1 and

O2S B2 S2) displayed on the Techstream.

HINT:



The Control the Injection Volume for A/F sensor 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.

VOLTAGE REFERENCE

VOLTAGE REFERENCE

Tester Display (Sensor)

Injection Volume Status

Voltage

AFS B1 S1 or AFS B2 S1 (A/F)

+25%

Rich

Less than 3.0 V

AFS B1 S1 or AFS B2 S1 (A/F)

-12.5%

Lean More than 3.35 V

O2S B1 S2 or O2S B2 S2 (HO2)

+25%

Rich More than 0.55 V

O2S B1 S2 or O2S B2 S2 (HO2)

-12.5%

Lean

Less than 0.4 V

NOTE:

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.

Case

A/F Sensor (Sensor 1) Output

Voltage

HO2 Sensor (Sensor 2)

Output Voltage

Main Suspected Trouble Area

1

-

2



A/F sensor



A/F sensor heater



A/F sensor circuit

3



HO2 sensor



HO2 sensor heater



HO2 sensor circuit



Injector

2008 Toyota Tundra

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



Following the Control the Injection Volume for A/F sensor procedure enables technicians to check and
graph the voltage outputs of both the A/F and HO2 sensors.



To display the graph, enter the following menus: Powertrain/Engine and ECT/Active Test/Control the
Injection Volume for A/F Sensor/A/F Control System/AFS B1 S1 and O2S B1 S2 or AFS B2 S1 and O2S
B2 S2.

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 the Techstream. Freeze frame data records 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.

1. READ DTC OUTPUT

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch ON and turn the Techstream ON.

c. Enter the following menus: Powertrain/Engine and ECT/Trouble Codes.

d. Read the DTCs.

Result

RESULT CHART

B : Go to step 8

C : Go to step 6

D : Go to step 17

A : Go to next step

4



Fuel pressure



Gas leakage from exhaust
system (Air-fuel ratio
extremely rich or lean)

Display (DTC Output) Proceed To

P0138 or P0158

A

P0137 or P0157

B

P0136 or P0156

C

P0139 or P0159

D

2008 Toyota Tundra

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