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 |
|---|---|---|
| Rear window defogger system does not operate (for Manual Air Conditioning System) | Heater control sub-assembly | |
| Rear window defogger wire | - | |
| Main body ECU (instrument panel junction block assembly) | - | |
| Harness or connector | - | |
| Rear window defogger system does not operate (for Automatic Air Conditioning System) | LIN communication line | |
| Main body ECU (instrument panel junction block assembly) | - | |
| Air conditioning control assembly | - | |
| Air conditioning amplifier assembly | - | |
| Harness or connector | - | |
| Rear window defogger, quick heater and mirror heater do not operate* | Power steering system (battery voltage reduction history) |
Tech Tips
*: As the operation of the rear window defogger, quick heater and mirror heater may be limited due to battery voltage reduction history in the power steering system, proceed according to "How to Proceed with Troubleshooting".