Toyota Tundra Service Manual: Test Mode Procedure

TEST MODE PROCEDURE

WARNING LIGHT AND INDICATOR LIGHT INITIAL CHECK

(a) When the ignition switch is turned to ON, check that the ABS warning light, brake warning light, TRAC OFF indicator light, VSC OFF indicator light, slip indicator light and AUTO LSD indicator light come on for approximately 3 seconds.

HINT:

• When the brake fluid level is low or the vacuum inside the brake booster decreases, the brake warning light comes on.
• If the skid control ECU (brake actuator assembly) stores a DTC, the ABS warning and slip indicator lights will come on.
• If any of the indicators remains on or does not come on, proceed to troubleshooting for the light circuits listed below.

SENSOR CHECK USING TEST MODE (SIGNAL CHECK)

NOTICE:

Perform Test Mode (Signal Check) with the vehicle stopped.

HINT:

• DTCs are stored if any malfunctions are detected during the check of each sensor.
• When entering Test Mode (Signal Check), the skid control ECU (brake actuator assembly) communicates with the millimeter wave radar sensor assembly to judge whether the vehicle is equipped with the pre-collision system. Therefore, do not exit Test Mode (Signal Check) within 5 seconds of entering Test Mode (Signal Check) (w/ Pre-collision System).

(a) Procedure to enter Test Mode (Signal Check)

(1) Turn the ignition switch off.

(2) Check that the steering wheel is centered.

(3) Check that the shift lever is in P.

(4) Connect the Techstream to the DLC3.

(5) Turn the ignition switch to ON.

(6) Turn the Techstream on.

(7) Switch the skid control ECU (brake actuator assembly) to Test Mode (Signal Check) using the Techstream. Enter the following menus: Chassis / ABS/VSC/TRAC / Utility / Signal Check.

HINT:

Do not exit Test Mode (Signal Check) within 5 seconds of entering Test Mode (Signal Check). If Test Mode (Signal Check) is exited within 5 seconds of entering Test Mode (Signal Check), DTC U0235 may be stored. If DTC U0235 is output after exiting Test Mode (Signal Check), enter Test Mode (Signal Check) again, wait at least 5 seconds, then recheck for DTCs (w/ Pre-collision System).

(8) Check that the ABS warning and slip indicator lights come on for several seconds and then blink in the Test Mode (Signal Check) pattern.

HINT:

If the ABS warning and slip indicator lights do not blink, inspect the ABS warning and slip indicator light circuits.

(9) Check the ABS sensors.

HINT:

Check that the ABS warning light is blinking in the Test Mode (Signal Check) pattern before performing the following ABS sensor checks.

(b) Lost Booster Pressure Judgment Check

NOTICE:

Perform this check in the lost booster pressure state (vacuum in the booster is released by pumping the brake pedal).

(1) Turn the ignition switch to ON.

(2) Release the parking brake.

NOTICE:

Before releasing the parking brake, move the shift lever to P for safety.

(3) Check that the brake warning light comes on when depressing the brake pedal with a force of 67 N (6.8 kgf, 15.1 lbf) or more for 1 second or more. (The lost booster pressure state is judged to be normal.)

(4) Start the engine while depressing the brake pedal with a force of 67 N (6.8 kgf, 15.1 lbf) or more for 1 second or more.

(5) Check that the brake warning light goes off when quickly releasing the brake pedal. (The lost booster pressure state is judged to be normal.)

NOTICE:

If rechecking after the engine has started, end Test Mode, enter Test Mode again, and release vacuum in the booster by pumping the brake pedal prior to rechecking.

HINT:

If the lost booster pressure state is not judged to be normal, the brake warning light comes on and Test Mode inspection item (Judgment of Failure State) is displayed.

(c) Speed Sensor Check

(1) Drive the vehicle straight-ahead.

Accelerate the vehicle to a speed of 45 km/h (28 mph) or more for several seconds.

HINT:

• The speed sensor check may not complete if wheelspin occurs.
• The speed sensor check may not complete if the speed sensor check is started while turning the steering wheel.

NOTICE:

After the ABS warning light goes off, if the vehicle speed exceeds 80 km/h (50 mph), a sensor check code will be stored again.

Decelerate or stop the vehicle before the speed reaches 80 km/h (50 mph).

(2) Check that the ABS warning light goes off.

HINT:

• The ABS warning light goes off when the sensor check has completed.
• The ABS warning light comes on immediately after a malfunction has been detected during the speed sensor check.

(3) Stop the vehicle.

HINT:

When the sensor check has completed, the ABS warning light goes off while the vehicle is being driven, and blinks in the Test Mode (Signal Check) pattern while the vehicle is stopped.

NOTICE:

If the sensor check has not completed, the ABS warning light will blink while the vehicle is being driven and the ABS will not operate.

(d) VSC OFF switch (traction control switch) Check

(1) Press the VSC OFF switch (traction control switch).

(2) Check that the VSC OFF indicator light comes on.

(3) Press the VSC OFF switch (traction control switch) again.

(e) End of Sensor Check

(1) If the sensor checks have completed, the ABS warning light blinks in the Test Mode (Signal Check) pattern when the vehicle is stopped and the ABS warning light goes off while the vehicle is being driven.

NOTICE:

If the sensor checks have not completed, the ABS warning light will blink while the vehicle is being driven and the ABS will not operate.

(f) End of Test Mode (Signal Check)

(1) Turn the ignition switch off and disconnect the Techstream.

(g) Test Mode (Signal Check) Inspection Item Chart