For 1990-2009 cars only
Important: The following steps must be completed before using the symptom tables.
- Perform the Theft Deterrent Diagnostic System Check for immobilizer concerns. Perform the BCM Diagnostic System Check for the Content Theft Deterrent (CTD) system before using the following Symptom Tables in order to verify that all of the following are true:
- Review the system operation in order to familiarize yourself with the system functions. Refer to Content Theft Deterrent (CTD) Circuit Description .
| • | There are no DTCs set. |
| • | The control module(s) can communicate via the serial data link. |
Visual/Physical Inspection
| • | Inspect for aftermarket devices which could affect the operation of the HVAC System. Refer to Checking Aftermarket Accessories in Wiring Systems. |
| • | Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom. |
Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:
