Toyota Tundra. Manual — part 1234

TYPICAL ENABLING CONDITIONS

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

COMPONENT OPERATING RANGE

FAIL-SAFE

When this DTC, or other DTCs relating to ETCS (Electronic Throttle Control System) malfunctions, are set, the
ECM enters fail-safe mode. During fail-safe mode, the ECM cuts the current to the throttle actuator, and the
throttle valve is returned to a 6° throttle angle by the return spring. The ECM then adjusts the engine output by
controlling the fuel injection (intermittent fuel-cut) and ignition timing, in accordance with the accelerator pedal
opening angle, to allow the vehicle to continue at a minimal speed. If the accelerator pedal is depressed firmly
and gently, the vehicle can be driven slowly. Fail-safe mode continues until a pass condition is detected, and the
ignition switch is then turned OFF.

WIRING DIAGRAM

Required Sensors/Components (Related)

None

Frequency of Operation

Continuous

Duration

0.8 seconds

MIL Operation

Immediate

Sequence of Operation

None

Monitor runs whenever following DTCs not present

None

Battery voltage

8 V or more

Electronic throttle actuator power

ON

Throttle actuator power supply voltage (+BM)

Less than 4 V

Throttle actuator power supply voltage (+BM)

11 to 14 V

2008 Toyota Tundra

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

Fig. 191: Throttle Actuator Control Motor Current Range / Performance - Wiring Diagram

INSPECTION PROCEDURE

HINT:

Read freeze frame data using the Techstream. Freeze frame data records the engine condition when
malfunctions are detected. When troubleshooting, freeze frame date 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 date
from the time the malfunction occurred.

1. READ VALUE USING TECHSTREAM (+BM VOLTAGE)

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/All Data/+BM Voltage.

e. Read the value displayed on the Techstream.

Standard voltage: 11 to 14 V

NG : Go to step 4

OK : Go to next step.

2008 Toyota Tundra

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

2. INSPECT BATTERY

a. Check that the battery is not depleted.

OK: Battery is not depleted

NG : REPLACE BATTERY

OK : Go to next step.

3. CHECK BATTERY TERMINAL

a. Check that the battery terminals and ECM ground are not loose or corroded.

OK: Battery terminals and ECM ground are not loose or corroded

NG : REPAIR OR REPLACE BATTERY TERMINAL

OK : CHECK FOR INTERMITTENT PROBLEMS (See CHECK FOR INTERMITTENT
PROBLEMS )

4. CHECK FUSE (ETCS)

a. Remove the ETCS fuse from the engine room relay block, junction block.

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

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

NG : CHECK FOR SHORTS IN ALL HARNESSES AND CONNECTORS CONNECTED TO
FUSE AND REPLACE FUSE

Tester Connection Condition Specified Condition

ETCS fuse

Always

Below 1 ohms

2008 Toyota Tundra

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

Fig. 192: Identifying ETCS Fuse

OK : Go to next step.

5. CHECK HARNESS AND CONNECTOR (ECM - ETCS FUSE, ETCS FUSE - BATTERY)

a. Check the harness and connector between the ETCS fuse and ECM.

1. Remove the ETCS fuse from the engine room relay block, junction block.

2. Disconnect the D74 ECM connector.

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

Standard resistance (Check for open)

TESTER CONNECTION SPECIFIED CONDITION

Standard resistance (Check for short)

TESTER CONNECTION SPECIFIED CONDITION

b. Check the harness and connector between the ETCS fuse and positive (+) battery terminal.

1. Remove the ETCS fuse from the engine room relay block, junction block.

2. Disconnect the cable from the positive (+) battery terminal.

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

Standard resistance (Check for open)

Tester Connection

Condition Specified Condition

ETCS fuse (2) - D74-41 (+BM) Always

Below 1 ohms

Tester Connection

Condition Specified Condition

ETCS fuse (2) or D74-41 (+BM) - Body ground Always

10 kohms or higher

2008 Toyota Tundra

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