Tech Tips
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.
Inspect the fuses and relays related to this system before inspecting the suspected areas below.
| Symptom | Suspected Area | See page |
|---|---|---|
| System does not operate at all (Initial check function also does not operate) | Clearance warning ECU power source circuit | |
| Clearance warning buzzer circuit | ||
| Clearance warning ECU assembly | ||
| Clearance sonar (rear corner sensor) does not operate (Initial check function operates normally) | Rear clearance sonar sensor LH circuit | |
| Rear clearance sonar sensor RH circuit | ||
| Clearance warning ECU assembly | ||
| Back sonar (rear center sensor) does not operate (Initial check function operates normally) | Back sonar sensor LH circuit | |
| Back sonar sensor RH circuit | ||
| Clearance warning ECU assembly | ||
| Clearance sonar and back sonar operate when reverse (R) has not been selected, or does not operate even when reverse (R) has been selected | Reverse signal circuit | |
| Clearance warning ECU assembly | ||
| Sonar detection operation is normal, but clearance sonar main switch indicator does not illuminate | Clearance warning ECU power source circuit | |
| Clearance sonar main switch (Inspection) | ||
| Clearance warning ECU assembly | ||
| Sonar detection operation is normal, but buzzer operation is intermittent | Clearance warning buzzer circuit | |
| Clearance warning ECU assembly | ||
| With the light control switch turned to the TAIL or HEAD position while the Toyota parking assist-sensor system is operating, the operation indicator on the clearance sonar main switch (back sonar or clearance sonar switch assembly) does not dim. | Illumination circuit | |
| Back sonar or clearance sonar switch assembly | ||
| Clearance warning ECU assembly |