HVAC System - Automatic

DIAGNOSTIC SYSTEM CHECK - HVAC SYSTEMS - AUTOMATIC

TEST DESCRIPTION

Steps 1-7:

Steps 8-9:

The numbers below refer to the step numbers on the diagnostic table.
3. Lack of communication may be due to a malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
5. Determine if the HVAC control module, body control module, or powertrain control module have set DTC's which may affect HVAC operation are present.
6. The presence of DTCs which begin with "U" indicate some other module is not communicating.
7. Answer Yes if the first three characters of the DTC name begins with B1O; regardless of the last two characters.