Toyota Tundra. Manual — part 1354

Fig. 86: Vehicle Speed Graph

HINT:

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch to ON.

c. Turn the Techstream ON.

d. Clear DTCs. (See DTC CHECK/CLEAR ).

e. Enter the following menus: Powertrain/Engine and ECT/Monitor.

f. Check that O2 Sensor/status2 is Incomplete.

g. Start the engine and warm it up.

h. Drive the vehicle at between 40 mph and 70 mph (64 km/h and 113 km/h) for at least 10 minutes.

i. Those items will change to Complete as O2 Sensor/Status2 monitor operates.

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

k. Check if any DTCs (any pending DTCs) are set.

HINT:

If O2 Sensor/status2 does not change to Complete, and any pending DTCs fail to set, extend the driving
time.

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

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

malfunctioning.

The following instructions describe how to conduct the Control the Injection Volume for A/F sensor operation
using the Techstream.

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. 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 OUTPUT REFERENCE

AIR-FUEL RATIO BLINKING PATTERN

Tester Display (Sensor)

Injection Volume Status

Voltage

AFS B1S1 or AFS B2S1 (A/F)

+25%

Rich

Less than 3.0 V

AFS B1S1 or AFS B2S1 (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

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-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.



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 OUTPUT DTC

a. Connect the Techstream to the DLC3.

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

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

d. Read DTCs.

Result

RESULT REFERENCE

B : Go to step 13

3



HO2 sensor



HO2 sensor heater



HO2 sensor circuit

4



Injector



Fuel pressure



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

Result

Proceed To

P0138 or P0158 is output

A

P0137 or P0157 is output

B

P0136 or P0156 is output

C

P0139 or P0159 is output

D

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

C : Go to step 6

D : Go to step 17

A : Go To Next Step

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

SENSOR)

a. Connect the Techstream to the DLC3.

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

c. Enter the following menus: Powertrain/Engine and ECT/Data List/A/F Control System/02S B1 S2

or 02S B2 S2.

d. Allow the engine to idle.

e. Read the Heated Oxygen (HO2) sensor output voltage while idling.

Result

RESULT REFERENCE

B : Go to step 5

A : Go To Next Step

3. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT)

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

b. Disconnect the D74 ECM connector.

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

Standard resistance

STANDARD RESISTANCE SPECIFICATION

Result

Proceed To

More than 1.2 V

A

Less than 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 (2UZ-FE) - Tundra