WARNING LIGHT AND INDICATOR LIGHT INITIAL CHECK
When the engine switch is turned on (IG), check that the ABS warning, brake warning, TRC OFF indicator, VSC OFF indicator and slip indicator lights all come on for approximately 3 seconds.
If a DTC is stored by the skid control ECU (brake actuator assembly), the ABS warning and slip indicator lights remain on.
If any of the indicators remains on or does not come on, proceed to troubleshooting for the light circuits listed below.
When the brake fluid level is low, the brake warning light comes on.
| Trouble Area | See Procedure |
|---|---|
| ABS warning light circuit (Remains on) | |
| ABS warning light circuit (Does not come on) | |
| Brake warning light circuit (Remains on) | |
| Brake warning light circuit (Does not come on) | |
| TRC OFF indicator light circuit (Remains on) | |
| TRC OFF indicator light circuit (Does not come on) | |
| VSC OFF indicator light circuit (Remains on) | |
| VSC OFF indicator light circuit (Does not come on) | |
| Slip indicator light circuit (Remains on) | |
| Slip indicator light circuit (Does not come on) |
SENSOR CHECK USING TEST MODE (SIGNAL CHECK)
VSC does not operate in Test Mode (Signal Check), regardless of whether the sensor check is normal or abnormal.
When a malfunction occurs in an ABS system sensor, the ABS warning light illuminates.
When a malfunction occurs in a VSC system sensor, the slip indicator light illuminates.
When entering Test Mode (Signal Check), the skid control ECU (brake actuator assembly) communicates with the driving support ECU 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).
Procedure to enter Test Mode (Signal Check)
Turn the engine switch off.
Check that the steering wheel is centered.
Check that the shift lever is in P.
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Switch the skid control ECU (brake actuator assembly) to Test Mode (Signal Check) using the GTS. Enter the following menus: Chassis / ABS/VSC/TRC / Utility / Signal Check.
| Tester Display |
|---|
| Signal Check |
Signals related to the VSC system can be inspected by performing a Test Mode (Signal Check) inspection. During the inspection, the display of items determined normal by the skid control ECU (brake actuator assembly) changes from incomplete to complete.
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 U1104 may be stored. If DTC U1104 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).
Check that the ABS warning and slip indicator lights come on for several seconds and then blink in the Test Mode pattern.
If the ABS warning and slip indicator lights do not blink, inspect the ABS warning and slip indicator light circuits.
Check the ABS sensors.
Check that the ABS warning light is blinking in the Test Mode pattern before performing the following ABS sensor checks.
Acceleration Sensor Check
Keep the vehicle stationary on a level surface for 1 second or more.
The acceleration sensor check can be performed by following the master cylinder pressure sensor check procedure below.
Lost Booster Pressure Judgment Check and Master Cylinder Pressure Sensor Zero Point Calibration
Depress the brake pedal several times to release vacuum from the brake booster assembly with the engine stopped.
Turn the engine switch on (IG).
Check that the brake warning light comes on when depressing the brake pedal with a force of 59.0 N (6.0 kgf, 13.2 lbf) or more for 1 second or more. (The lost booster pressure state is judged to be normal.)
Start the engine while depressing the brake pedal with a force of 59.0 N (6.0 kgf, 13.2 lbf) or more for 1 second or more.
Check that the brake warning light goes off when quickly releasing the brake pedal. (The lost booster pressure state is judged to be normal.)
Leave the vehicle for 1 second or more. (Master cylinder pressure sensor zero point calibration)
If depressing the brake pedal slowly or repeatedly, the master cylinder pressure sensor zero point calibration is not performed normally.
If the lost booster pressure judgment check results are not normal, then the master cylinder pressure sensor check cannot be performed.
If rechecking after the engine has started, end Test Mode (Signal Check), enter Test Mode (Signal Check) again, and release vacuum in the booster by pumping the brake pedal prior to rechecking.
If the lost booster pressure state is not judged to be normal, the brake warning light comes on and Test Mode (Signal Check) inspection item (Output Master Cylinder Pressure Sensor) is displayed.
Master Cylinder Pressure Sensor Check
Start the engine.
Leave the vehicle in a stationary condition and release the brake pedal for 1 second or more, and quickly and continuously depress the brake pedal with a force of 98 N (10 kgf, 22.0 lbf) for 1 second.
Check that the ABS warning light stays on for 3 seconds.
Confirm that the ABS warning light comes on.
While the ABS warning light stays on, continue to depress the brake pedal with a force of 98 N (10 kgf, 22.0 lbf) or more.
The ABS warning light comes on for 3 seconds every time the preceding brake pedal operation is performed.
Speed Sensor Check
Before performing the speed sensor signal check, complete the acceleration sensor and master cylinder pressure sensor checks.
Start the engine.
Drive the vehicle straight ahead.
Accelerate the vehicle to a speed of 45 km/h (28 mph) or more for several seconds.
The speed sensor check may not complete if the speed sensor check is started while turning the steering wheel or spinning the wheels.
After the ABS warning light goes off, if 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).
The sensor check may not complete if wheelspin occurs.
The ABS warning light comes on immediately if a malfunction is detected during the speed sensor check.
Check that the ABS warning light goes off.
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.
Stop the vehicle.
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.
When the sensor check has completed, the ABS warning light goes off while the vehicle is being driven, and blinks in the Test Mode pattern while the vehicle is stopped.
VSC Sensor Check
Check that the slip indicator light is blinking in the Test Mode pattern before performing the following VSC sensor check.
VSC OFF Switch (Combination Switch Assembly) Check
Press the VSC OFF switch (combination switch assembly).
Check that the VSC OFF indicator light comes on.
Press the VSC OFF switch (combination switch assembly) again.
End of Sensor Check
If the sensor check is completed, the ABS warning light and slip indicator light blinks in the Test Mode pattern when the vehicle stops and the ABS warning light is off while the vehicle is being driven.
When Test Mode (Signal Check) is started with the GTS and all items display complete, the sensor check ends.
If the sensor check is not complete, the ABS warning light blinks when the vehicle is in motion and the ABS does not operate.
If a DTC is detected in Test Mode (Signal Check), the ABS warning light or slip indicator light illuminates.
End of Test Mode (Signal Check)
End Test Mode (Signal Check) using the GTS
Turn the engine switch off and enter normal mode.
Remove the GTS.
Test Mode (Signal Check) Inspection Item Chart
| Item Name | Range | Judgment Description | Trouble Area |
| Output Signal of Front Speed Sensor RH | Incomplete/complete | Check for foreign matter, check the gap between the sensor and rotor |
|
| Output Signal of Front Speed Sensor LH | Incomplete/complete | Check for foreign matter, check the gap between the sensor and rotor |
|
| Output Signal of Rear Speed Sensor RH | Incomplete/complete | Check for foreign matter, check the gap between the sensor and rotor |
|
| Output Signal of Rear Speed Sensor LH | Incomplete/complete | Check for foreign matter, check the gap between the sensor and rotor |
|
| Change in Output Signal of Front Speed Sensor RH | Incomplete/complete |
|
|
| Change in Output Signal of Front Speed Sensor LH | Incomplete/complete |
|
|
| Change in Output Signal of Rear Speed Sensor RH | Incomplete/complete |
|
|
| Change in Output Signal of Rear Speed Sensor LH | Incomplete/complete |
|
|
| Output Voltage Deceleration Sensor | Incomplete/complete | Check the acceleration sensor output voltage |
|
| Memory System Information | Incomplete/complete | Check stored system information (skid control ECU (brake actuator assembly)) against vehicle specification |
|
| Output Master Cylinder Pressure Sensor | Incomplete/complete |
|
|
| Judgment of Failure State | Incomplete/complete | Check that the brake pedal load sensing switch is normal |
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