Displaying & Reading Trouble Codes

The C68 Electronic Climate Control System is equipped with an on-board diagnostic function which allows the Heater And A/C Control Assembly to detect certain system faults. The diagnostic function is also used to display data parameters. If the Heater And A/C Control Assembly detects a fault in the system, the C° or F° annunciator will flash during the first 2 minutes of vehicle operation.

To Enter the Diagnostic Mode:

1. Press the "OUTS TEMP" button then press the "BI-LEV" button. Hold both buttons for 3 seconds. -00 will be displayed, indicating entry to the diagnostic mode.

2. -00 is also called a diagnostic pointer. A diagnostic pointer indicates the parameter which can be displayed (see list in illustration). To move through the list, press the "FAN" button. To display the information in a diagnostic pointer, press the "OUTS TEMP" button.

3. Diagnostic pointers -40, -41, and -42 are output commands which allow you to control the position of the Air Mix Valve, the prograin number, or the air delivery mode. To enter an output command, press the "OUTS TEMP" button when the desired pointer number is displayed; then use the "COOL"and "WARM" buttons to change the value.

4. To exit the diagnostic mode, press the "OFF" button. To exit from a diagnostic pointer, but not from the diagnostic mode, press the "FAN" button.