Diagnostic System Check - HVAC System - Automatic

DIAGNOSTIC SYSTEM CHECK

TEST DESCRIPTION

Steps 1-8:

The number(s) below refer to the step number(s) on the diagnostic table.
3. 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.
4. Determine if the dash integration module powertrain control module or instrument panel integration module have set DTC's which may affect HVAC operation are present.
5. 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.
6. Answer Yes if the first three characters of the DTC name begins with B10; regardless of the last two characters. If a B1000 code is set, answer No to the question.
8. Be sure to follow the diagnostic table for B1000 in the HVAC Systems-Automatic section. Do not use the table in Body Control Module System.