How To Troubleshoot The Heating And A/C Systems

How to Troubleshoot the Heating and A/C Systems

How to Use the Self-Diagnostic Function

The HVAC control unit has a self-diagnostic function for heating, ventilation, and air conditioning system. To run the self-diagnostic function, do the following:

1. Turn the ignition switch to LOCK (0).

2. Press and hold the RECIRCULATION CONTROL button and REAR WINDOW DEFOGGER button, turn the ignition switch to ON (II).

3. The recirculation indicator turns on for 2 seconds, then the self-diagnostic function begins.

NOTE:

- The blower motor will run at various speeds when in the self-diagnostic mode.
- In the case of multiple problems, the recirculation indicator will blink the lowest number DTC only.
- If no DTCs are found, the indicator will not blink.





Example of DTC Indication Pattern (DTC 3)









Clear the DTCs

When the problem is repaired, DTCs will automatically clear.

Max Cool Position Function

When the mode control button is in the MAX A/C position, the HVAC control unit will automatically select the recirculation mode and turn the A/C on. If the recirculation button is pressed when in MAX A/C mode, MAX A/C turns off. If the A/C button is pressed when in MAX A/C mode, the A/C turns off.