Diagnostic System Check - HVAC System - Automatic
TEST DESCRIPTIONSteps 1-5:
The number(s) below refer to the step number(s) on the diagnostic table.
2. Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
3. DTCs that may be stored in the HVAC Control Module will be retrieved. These DTCs must be addressed prior to proceeding to the symptoms list.
4. The presence of DTCs which begin with U indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.