Displaying & Reading Trouble Codes

ON-BOARD DIAGNOSTIC MODE
The type C68 air conditioning is equipped with an on-board diagnostic feature which allows the HVAC Control Assembly to detect certain system faults. The diagnostic feature can also be used to display certain data parameters. If the HVAC Control Assembly detects a fault in the system, the C° (or F°) indicator will flash during the first two minutes of vehicle operation.

Entry into the diagnostic mode is gained by depressing the "OUTS TEMP" and "BI-LEV" buttons at the same time. Once the diagnostic mode is entered, any trouble codes stored will be displayed. If none are present, 00 will be displayed.

If the "WARM" button is depressed after the trouble codes have been displayed, the data mode will be entered. The information available in the data mode is displayed in units used by the computer which may not be of use in observing the system. To exit the diagnostic mode, press any mode button.

A list of Trouble Codes and their meanings follow:

Trouble Code Description
00 No System Faults

01 OR 101 Inside Air Temperature Sensor short

02 OR 102 Inside Air Temperature Sensor open

03 OR 103 Outside Air Temperature Sensor short

04 OR 104 Outside Air Temperature Sensor open

05 OR 105 Air Temperature Valve Feedback Circuit

09 OR 109 Serial Data line failure

IMPORTANT:
A two digit trouble code indicates the fault is current. A three digit trouble code indicates an intermittent fault.