Initial Inspection and Diagnostic Overview

INSPECTION AND VERIFICATION

1. Verify the customer's concern by operating the climate control system to duplicate the condition.

Visual Inspection Chart:

2. Inspect to determine if one of the following mechanical or electrical concerns apply:
3. As pinpoint tests and measurements are being carried out, be sure to inspect for any disconnected, loose fitting, or incorrectly installed component, module and in-line electrical connectors and pins.
4. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
5. If the cause is not visually evident, connect a scan tool to the data link connector and select the vehicle to be tested from the scan tool menu. If the scan tool does not communicate with the vehicle:
- check that the program card is correctly installed.
- check the connections to the vehicle.
- check the ignition switch position.

6. If the scan tool still does not allow with the vehicle selection to be entered, refer to the scan tool manual.
7. Carry out the DATA LINK DIAGNOSTIC TEST using the scan tool. If the scan tool responds with:
- SCP+, SCP-, or UBP CIRCUITS FAULT = ALL ECUS NO RESP/NOT EQUIP, refer to Module Communications Network (Information Bus) to diagnose the network concern.
- If the powertrain control module (PCM) is not listed for a communication concern, turn the A/C controls to OFF and carry out the self-test diagnostics for the PCM.

8. If any PCM diagnostic trouble codes (DTCs) are retrieved and related to the concern, go to the Diagnostic Trouble Code (DTC) Index to continue diagnostics. Diagnostic Trouble Code Tests and Associated Procedures
9. If no DTCs related to the concern are retrieved, GO to Symptom Chart to continue diagnostics. Symptom Related Diagnostic Procedures