ELECTRONICALLY CONTROLLED BRAKE SYSTEM PROBLEM SYMPTOMS TABLE
If there are no DTCs but the problem still occurs, check the suspected areas for each problem symptom in the order given in the table below and proceed to the relevant troubleshooting page.
Note
When replacing the skid control ECU assembly, sensors, etc., make sure that the power switch is turned off, the stop light switch assembly is off, and 2 minutes have elapsed since the driver door was closed.
Tech Tips
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Since the hydraulic passage is blocked off by the master cut solenoid during electronically controlled brake system control, there are no kickbacks (vibrations) to the brake pedal, creating little sound even while the ABS is operating.
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Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, 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.
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Inspect the fuses and relays related to this system before inspecting the suspected areas below.
| Symptom | Suspected Area | Link |
|---|---|---|
| ABS, BA and/or EBD does not operate | Use a chassis dynamometer, etc. to check the electronically controlled brake system operation. | - |
| Check again to see if DTCs are output. (If DTCs are output, perform diagnosis based on the DTCs that are output.) | ||
| Power source circuit | ||
| Front speed sensor circuit | ||
| Rear speed sensor circuit | ||
| Check the brake actuator assembly using the GTS. (Check brake actuator assembly operation using the Active Test function.) If abnormal, check the hydraulic circuit for leaks (for LHD). | ||
| Check the brake actuator assembly using the GTS. (Check brake actuator assembly operation using the Active Test function.) If abnormal, check the hydraulic circuit for leaks (for RHD). | ||
| If the symptoms still occur even after the above suspected areas have been inspected and proved to be normal, replace the skid control ECU assembly (for LHD). | ||
| If the symptoms still occur even after the above suspected areas have been inspected and proved to be normal, replace the skid control ECU assembly (for RHD). | ||
| ABS, BA and/or EBD does not operate efficiently | Check again to see if DTCs are output. (If DTCs are output, perform diagnosis based on the DTCs that are output.) | |
| Front speed sensor circuit | ||
| Rear speed sensor circuit | ||
| Check the brake actuator assembly using the GTS. (Check brake actuator assembly operation using the Active Test function.) If abnormal, check the hydraulic circuit for leaks (for LHD). | ||
| Check the brake actuator assembly using the GTS. (Check brake actuator assembly operation using the Active Test function.) If abnormal, check the hydraulic circuit for leaks (for RHD). | ||
| If the symptoms still occur even after the above suspected areas have been inspected and proved to be normal, replace the skid control ECU assembly (for LHD). | ||
| If the symptoms still occur even after the above suspected areas have been inspected and proved to be normal, replace the skid control ECU assembly (for RHD). | ||
| ABS warning light abnormal (Remains on) | ABS warning light circuit | |
| Skid control ECU assembly (for LHD) | ||
| Skid control ECU assembly (for RHD) | ||
| ABS warning light abnormal (Does not come on) | ABS warning light circuit | |
| Skid control ECU assembly (for LHD) | ||
| Skid control ECU assembly (for RHD) | ||
| Brake warning light / red (malfunction) abnormal (Remains on) | Brake fluid level warning switch circuit | |
| Brake warning light / red (malfunction) circuit | ||
| Skid control ECU assembly (for LHD) | ||
| Skid control ECU assembly (for RHD) | ||
| Brake warning light / red (malfunction) abnormal (Does not come on) | Brake warning light / red (malfunction) circuit | |
| Skid control ECU assembly (for LHD) | ||
| Skid control ECU assembly (for RHD) | ||
| VSC and/or TRC does not operate | Check again to see if DTCs are output. (If DTCs are output, perform diagnosis based on the DTCs that are output.) | |
| Power source circuit | ||
| Check the hydraulic circuit for leaks. | - | |
| Front speed sensor circuit | ||
| Rear speed sensor circuit | ||
| Yaw rate and acceleration sensor circuit (Power supply malfunction) | ||
| Yaw rate and acceleration sensor circuit (Stuck and signal malfunction) | ||
| Steering angle sensor circuit | ||
| If the symptoms still occur even after the above suspected areas have been inspected and proved to be normal, replace the skid control ECU assembly (for LHD). | ||
| If the symptoms still occur even after the above suspected areas have been inspected and proved to be normal, replace the skid control ECU assembly (for RHD). | ||
| Brake warning light / yellow (minor malfunction) abnormal (Remains on) | Brake warning light / yellow (minor malfunction) circuit | |
| Skid control ECU assembly (for LHD) | ||
| Skid control ECU assembly (for RHD) | ||
| Brake warning light / yellow (minor malfunction) abnormal (Does not come on) | Brake warning light / yellow (minor malfunction) circuit | |
| Skid control ECU assembly (for LHD) | ||
| Skid control ECU assembly (for RHD) | ||
| Slip indicator light abnormal (Remains on) | Slip indicator light circuit | |
| Skid control ECU assembly (for LHD) | ||
| Skid control ECU assembly (for RHD) | ||
| Slip indicator light abnormal (Does not come on) | Slip indicator light circuit | |
| Skid control ECU assembly (for LHD) | ||
| Skid control ECU assembly (for RHD) | ||
| VSC OFF switch (Combination switch assembly) abnormal | VSC OFF switch (Combination switch assembly) circuit | |
| Skid control ECU assembly (for LHD) | ||
| Skid control ECU assembly (for RHD) | ||
| DTC check cannot be done | Check again to see if DTCs are output. (If DTCs are output, perform diagnosis based on the DTCs that are output.) | |
| TC and CG terminal circuit | ||
| If the symptoms still occur even after the above suspected areas have been inspected and proved to be normal, replace the skid control ECU assembly (for LHD). | ||
| If the symptoms still occur even after the above suspected areas have been inspected and proved to be normal, replace the skid control ECU assembly (for RHD). | ||
| Sensor check cannot be done | TS and CG terminal circuit | |
| Skid control ECU assembly (for LHD) | ||
| Skid control ECU assembly (for RHD) | ||
| Meter buzzer abnormal | Meter buzzer circuit | |
| Skid control ECU assembly (for LHD) | ||
| Skid control ECU assembly (for RHD) |