Initial Inspection and Diagnostic Overview

Self-diagnostic Function

The seat ventilation control unit has a thermistor self-diagnostic function. The control unit checks for an open or short in the thermistor, and it indicates the result by lighting the LEDs of the seat ventilation switch.

Entering the self-diagnostic function

1. Turn the ignition switch ON (II), and do the next step within 5 seconds.
2. Push the DOWN side of the seat ventilation switch three times, and the UP side six times, then the DOWN side three times.
3. If the system enters the self-diagnostic mode, all of the LEDs (A) turn on for 6 seconds, then indicate the result.
- If the three LEDs of the heater side turn on, the thermistor is faulty.
- If no LED turns on, the thermistor is OK.

NOTE: The system has a timer function.

- The fan motor timer: About 15 minutes after the fan motor HIGH position is ON, the control unit changes the fan motor speed and switch LED indicators from Hi to Mid.
- The seat heater timer: About 5 minutes after the heater temperature rises over 109.4 degrees F (43 degrees C), the control unit changes the heater temperature and switch LED indicators from Hi to Mid.

Ending the self-diagnostic function

Turn the ignition switch OFF, and the self-diagnostic mode is exited.