Reading and Clearing Diagnostic Trouble Codes

Self-Diagnosis Circuit Check
The Automatic Climate Control System has a built-in self-diagnosis feature. To run it, turn the ignition switch ON and turn the FAN switch to AUTO position. Wait for at least one minute on each TEMP display 18°C 164°F), 32°C 190°F). Then, push both the AUTO and OFF buttons on the control unit at the same time. Any problems in circuits "A" through "I" listed below will be indicated by the respective indicator coming on.

The climate control unit does not memorize which self-diagnosis indicator lights comes on. If you turn the ignition switch OFF, the indicator light memory will be lost.