Problem Symptoms Table
WARNING: This page is about a different car, the 2010 Lexus GS 450h. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
When replacing the skid control ECU, sensor, etc., make sure that the power switch is turned OFF, the stop light switch is off, and 2 minutes have elapsed since the driver's door was closed.
HINT:
- Use the table below to help determine the cause of the problem symptom. The potential causes of the symptoms are listed in order of probability in the "Suspected area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
- Inspect the fuses and relays related to this system before inspecting the suspected areas below.
- Since the oil passage is blocked off by the master cut solenoid during the electronically controlled brake system control, there is no kickback (vibration) to the brake pedal, creating a quiet operating sound even while the ABS is operating.
ELECTRONICALLY CONTROLLED BRAKE SYSTEM
| Symptom | Suspected Area | See |
|---|---|---|
| ABS, BA and/or EBD does not operate | 1. Use a chassis dynamometer, etc. to check the electronically controlled brake system operation | - |
| 2. Check the DTC again and make sure that the normal system code is output | Refer toDTC CHECK / CLEAR | |
| 3. IG power source circuit | Refer toDTC C1241/41: Low Battery Positive Voltage; DTC C1242/42: Open in IG1 / IG2 Power Source Circuit | |
| 4. Front speed sensor circuit | Refer toDTC C0200/31: Front Speed Sensor RH Circuit; DTC C0205/32: Front Speed Sensor LH Circuit; DTC C1271/71: Low Output Signal of Front Speed Sensor RH (Test Mode DTC); DTC C1272/72: Low Output Signal of Front Speed Sensor LH (Test Mode DTC) | |
| 5. Rear speed sensor circuit | Refer toDTC C0210/33: Rear Speed Sensor RH Circuit; DTC C0215/34: Rear Speed Sensor LH Circuit; DTC C1273/73: Low Output Signal of Rear Speed Sensor RH (Test Mode DTC); DTC C1274/74: Low Output Signal of Rear Speed Sensor LH (Test Mode DTC) | |
| 6. Check the brake actuator with the Techstream (Check brake actuator operation using the Active Test function) If abnormal, check the hydraulic circuit for leakage | Refer toON-VEHICLE INSPECTION | |
| 7. If the symptoms still occur even after the above circuits in suspected areas have been inspected and proved to be normal, replace the skid control ECU | Refer toREMOVAL | |
| ABS, BA and/or EBD does not operate efficiently | 1. Check the DTC again and make sure that the normal system code is output | Refer toDTC CHECK / CLEAR |
| 2. Front speed sensor circuit | Refer toDTC C0200/31: Front Speed Sensor RH Circuit; DTC C0205/32: Front Speed Sensor LH Circuit; DTC C1271/71: Low Output Signal of Front Speed Sensor RH (Test Mode DTC); DTC C1272/72: Low Output Signal of Front Speed Sensor LH (Test Mode DTC) | |
| 3. Rear speed sensor circuit | Refer toDTC C0210/33: Rear Speed Sensor RH Circuit; DTC C0215/34: Rear Speed Sensor LH Circuit; DTC C1273/73: Low Output Signal of Rear Speed Sensor RH (Test Mode DTC); DTC C1274/74: Low Output Signal of Rear Speed Sensor LH (Test Mode DTC) | |
| 4. Check the brake actuator with the Techstream (Check brake actuator operation using the Active Test function) If abnormal, check the hydraulic circuit for leakage | Refer toON-VEHICLE INSPECTION | |
| 5. If the symptoms still occur even after the above circuits in suspected areas have been inspected and proved to be normal, replace the skid control ECU | Refer toREMOVAL | |
| VSC and/or TR(A)C does not operate | 1. Check that traction control has not operated by carrying out diagnosis (Traction control does not operate while the VSC OFF switch is ON and the brake control warning light and slip indicator light are ON) | - |
| 2. Check the DTC again and make sure that the normal system code is output | Refer toDTC CHECK / CLEAR | |
| 3. IG power source circuit | Refer toDTC C1241/41: Low Battery Positive Voltage; DTC C1242/42: Open in IG1 / IG2 Power Source Circuit | |
| 4. Check the hydraulic circuit for leakage | - | |
| 5. Front speed sensor circuit | Refer toDTC C0200/31: Front Speed Sensor RH Circuit; DTC C0205/32: Front Speed Sensor LH Circuit; DTC C1271/71: Low Output Signal of Front Speed Sensor RH (Test Mode DTC); DTC C1272/72: Low Output Signal of Front Speed Sensor LH (Test Mode DTC) | |
| 6. Rear speed sensor circuit | Refer toDTC C0210/33: Rear Speed Sensor RH Circuit; DTC C0215/34: Rear Speed Sensor LH Circuit; DTC C1273/73: Low Output Signal of Rear Speed Sensor RH (Test Mode DTC); DTC C1274/74: Low Output Signal of Rear Speed Sensor LH (Test Mode DTC) | |
| 7. Yaw rate and acceleration sensor circuit | Refer toDTC C1234/34: Yaw Rate Sensor Malfunction; DTC C0371/71: Yaw Rate Sensor (Test Mode DTC); DTC C1243/43: Acceleration Sensor Stuck Malfunction; DTC C1244/44: Open or Short in Deceleration Sensor Circuit; DTC C1245/45: Acceleration Sensor Output Malfunction; DTC C1279/79: Deceleration Sensor Output Voltage Malfunction (Test Mode DTC); DTC C1381/97: Acceleration Sensor Power Supply Voltage Malfunction | |
| 8. Steering angle sensor circuit | Refer toDTC C1231/31: Steering Angle Sensor Circuit Malfunction | |
| 9. If the symptoms still occur even after the above circuits in suspected areas have been inspected and proved to be normal, replace the skid control ECU | Refer toREMOVAL | |
| Sensor signal check cannot be done | 1. TS and CG terminal circuit | Refer toTS and CG Terminal Circuit |
| 2. Skid control ECU | Refer toREMOVAL | |
| DTC check cannot be done | 1. Check the DTC again and make sure that the normal system code is output | Refer toDTC CHECK / CLEAR |
| 2. TC and CG terminal circuit | Refer toTC and CG Terminal Circuit | |
| 3. If the symptoms still occur even after the above circuits in suspected areas have been inspected and proved to be normal, replace the skid control ECU | Refer toREMOVAL | |
| ABS warning light abnormal (Remains on) | 1. ABS warning light occurs | Refer toABS Warning Light Remains ON |
| 2. Skid control ECU | Refer toREMOVAL | |
| ABS warning light abnormal (Does not come on) | 1. ABS warning light occurs | Refer toABS Warning Light does not Come ON |
| 2. Skid control ECU | Refer toREMOVAL | |
| Brake control warning light abnormal (Remains on) | 1. Brake control warning light circuit | Refer toBrake Control Warning Light Remains ON |
| 2. Skid control ECU | Refer toREMOVAL | |
| Brake control warning light abnormal (Does not come on) | 1. Brake control warning light circuit | Refer toBrake Control Warning Light does not Come ON |
| 2. Skid control ECU | Refer toREMOVAL | |
| Brake warning light abnormal (Remains on) | 1. Brake fluid level warning light switch circuit | Refer toDTC C1202/68: Master Reservoir Level Malfunction |
| 2. Brake warning light circuit | Refer toBrake Warning Light Remains ON | |
| 3. Skid control ECU | Refer toREMOVAL | |
| Brake warning light abnormal (Does not come on) | 1. Brake warning light circuit | Refer toBrake Warning Light does not Come ON |
| 2. Skid control ECU | Refer toREMOVAL | |
| Slip indicator light abnormal (Remains on) | 1. Slip indicator light circuit | Refer toSlip Indicator Light Remains ON |
| 2. Skid control ECU | Refer toREMOVAL | |
| Slip indicator light abnormal (Does not come on) | 1. Slip indicator light circuit | Refer toSlip Indicator Light does not Come ON |
| 2. Skid control ECU | Refer toREMOVAL | |
| VSC OFF indicator light abnormal (Remains on) | 1. VSC OFF indicator light circuit | Refer toVSC OFF Indicator Light Remains ON |
| 2. Skid control ECU | Refer toREMOVAL | |
| VSC OFF indicator light abnormal (Does not come on) | 1. VSC OFF indicator light circuit | Refer toVSC OFF Indicator Light does not Come ON |
| 2. Skid control ECU | Refer toREMOVAL | |
| Multi-information display (TR(A)C OFF indicator) abnormal (Remains on) | 1. Multi-information display (TR(A)C OFF indicator) circuit | Refer toTRAC OFF Indicator Light Remains ON |
| 2. Skid control ECU | Refer toREMOVAL | |
| Multi-information display (TR(A)C OFF indicator) abnormal (Does not come on) | 1. Multi-information display (TR(A)C OFF indicator) circuit | Refer toTRAC OFF Indicator Light does not Come ON |
| 2. Skid control ECU | Refer toREMOVAL | |
| Skid control buzzer abnormal | 1. Skid control buzzer circuit | Refer toSkid Control Buzzer Circuit |
| 2. Skid control ECU | Refer toREMOVAL |