WARNING LIGHT AND INDICATOR LIGHT INITIAL CHECK
When the engine switch is turned on (IG), check that the ABS warning light, brake system warning light (red indicator), VSC OFF indicator light, brake hold standby indicator light, brake hold operated indicator light and slip indicator light come on for approximately 3 seconds.
Tech Tips
When the brake fluid level is low, the brake system warning light (red indicator) comes on.
If the skid control ECU (brake actuator assembly) stores any DTCs, the ABS warning and slip indicator lights will come on.
If any of the indicators remain on or do not come on, proceed to troubleshooting for the light circuits listed below.
Trouble Area | See Procedure |
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ABS warning light circuit (Remains on) | |
ABS warning light circuit (Does not come on) | |
Brake system warning light (red indicator) circuit (Remains on) | |
Brake system warning light (red indicator) circuit (Does not come on) | |
Slip indicator light circuit (Remains on) | |
Slip indicator light circuit (Does not come on) | |
Brake hold standby indicator light circuit | |
Brake hold operated indicator light circuit |
ACTIVATE TEST MODE (SIGNAL CHECK)
Tech Tips
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, the skid control ECU 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 within 5 seconds of entering test mode.
Procedure to enter Test Mode (signal check).
Turn the engine switch on (IG).
Make sure the shift state is in park (P).
Apply the parking brake.
Put the steering wheel in the neutral position.
Turn the engine switch off and connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.
Enter the following menus: Chassis / ABS/VSC/TRC / Utility / Signal Check.
Tester Display |
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Signal Check |
Tech Tips
Signals related to the electronically controlled brake 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 within 5 seconds of entering test mode. If test mode is exited within 5 seconds of entering test mode, DTC U1104 may be stored. If DTC U1104 is output after exiting test mode, enter test mode again, wait at least 5 seconds, then recheck for DTCs.
Item Name | Range | Judgment Description | Trouble Area |
Output Signal of Front Speed Sensor RH | Incomplete/complete | Check for foreign matter, evaluate the gap between the sensor and rotor |
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Output Signal of Front Speed Sensor LH | Incomplete/complete | Check for foreign matter, evaluate the gap between the sensor and rotor |
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Output Signal of Rear Speed Sensor RH | Incomplete/complete | Check for foreign matter, evaluate the gap between the sensor and rotor |
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Output Signal of Rear Speed Sensor LH | Incomplete/complete | Check for foreign matter, evaluate the gap between the sensor and rotor |
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Change in Output Signal of Front Speed Sensor RH | Incomplete/complete |
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Change in Output Signal of Front Speed Sensor LH | Incomplete/complete |
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Change in Output Signal of Rear Speed Sensor RH | Incomplete/complete |
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Change in Output Signal of Rear Speed Sensor LH | Incomplete/complete |
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Output Voltage Deceleration Sensor | Incomplete/complete | Evaluate the acceleration sensor output voltage |
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Memory System Information | Incomplete/complete | Evaluate stored system information (skid control ECU (brake actuator assembly)) against vehicle specification |
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Output Master Cylinder Pressure Sensor | Incomplete/complete |
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Judgment of Failure State | Incomplete/complete | Check that the brake pedal load sensing switch is normal |
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ACCELERATION SENSOR CHECK
Enter Test Mode (signal check).
Keep the vehicle stationary on a level surface for 1 second or more.
Tech Tips
The acceleration sensor check can be performed with the master cylinder pressure sensor check 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 system warning light (red indicator) 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 system warning light (red indicator) 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)
Note
If the brake pedal is depressed slowly or repeatedly, the master cylinder pressure sensor zero point calibration will not complete 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, enter Test Mode again, and release vacuum in the booster by pumping the brake pedal prior to rechecking.
Tech Tips
If the lost booster pressure state is not judged to be normal, the brake system warning light (red indicator) comes on and Test Mode (signal check) inspection item (Output Master Cylinder Pressure Sensor) is displayed.
MASTER CYLINDER PRESSURE SENSOR CHECK
Enter Test Mode (signal 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 lbf) or more for 1 second.
Check that the ABS warning light stays on for 3 seconds.
Tech Tips
Ensure 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 lbf) or more.
The ABS warning light comes on for 3 seconds every time the brake pedal operation above is performed.
If the master cylinder pressure sensor check is not completed, depressing the brake pedal causes further decreases in vacuum in the brake booster, making the sensor check difficult to complete.
If the vacuum is insufficient, the master cylinder pressure sensor check may not be completed. In this case, run the engine at idle to obtain sufficient vacuum.
If the brake pedal is strongly depressed when the vacuum is insufficient, the brake system warning light (red indicator) may come on in accordance with booster pressure control. In this case, run the engine at idle to obtain sufficient vacuum.
SPEED SENSOR CHECK
Note
Before performing the speed sensor signal check, complete the acceleration sensor and master cylinder pressure sensor checks.
Enter Test Mode (signal check).
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 and check that the ABS warning light goes off.
The sensor check may not be completed if wheelspin occurs.
The ABS warning light blinks when the sensor check has been completed and the brake pedal is depressed.
The ABS warning light comes on immediately after a malfunction has been detected during the speed sensor check.
Stop the vehicle.
Note
The speed sensor check may not be completed if the sensor check is started with the steering wheel turned or one or more wheels spinning.
After the ABS warning light goes off and 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).
If the sensor check has not been completed, the ABS warning light blinks during driving and the ABS system does not operate.
Tech Tips
When the sensor check has been completed, the ABS warning light remains off during driving and blinks in the Test Mode (signal check) pattern while the vehicle is stationary.
END OF SENSOR CHECK
If the sensor check is completed, the ABS warning light and slip indicator light blink (Test Mode (signal check)) when the vehicle stops and the ABS warning light is off while the vehicle is being driven.
Note
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.