Buick Regal: Diagnostic Information and Procedures

 Symptoms - HVAC Systems - Automatic

NOTE: The following steps must be completed before using the symptom tables: 1. Perform the Diagnostic System Check - Vehicle before using the HVAC System Malfunction procedure in order to verify that all of the following are true: There are no DTCs set. The control modules can communicate via

 DTC B3715 or B3875

Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. DTC Descriptors D