Manual A/C-Heater

1. Verify the customer's concern by operating the manual A/C-heater controls to duplicate the condition.
2. Inspect to determine if one of the following mechanical or electrical concerns apply:

VISUAL INSPECTION CHART

Mechanical
- Vacuum hose damaged.
- A/C system damaged.
- Damaged drive belt.

Electrical
- Open fuse(s).
- Circuitry misrouted/damaged.
- Connectors damaged/disconnected.

3. If inspection reveals an obvious concern that can be readily serviced, correct the concern before continuing with Inspection and Verification.
4. If a concern remains after the inspection, use the Rotunda New Generation Star (NGS) Tester 007-00500 or equivalent connected to the Data Link Connector (DLC) and select the vehicle to be tested from the NGS menu.

If the vehicle selection cannot be entered:
- check that the program card is properly installed.
- check the connections to the vehicle.
- check the ignition switch position. If the NGS still does not allow the vehicle selection to be entered, refer to the New Generation Star Tester manual.
5. Perform the DATA LINK DIAGNOSTIC TEST using the NGS or equivalent. If the NGS responds with:
- CKT 914 and CKT 915 = ALL MODULE NO RESP/NOT EQUIP, go to Information Bus to diagnose a network concern.
- If the Powertrain Control Module (PCM) is not listed for a communication concern, turn the A/C function selector switch to OFF and execute self-test diagnostics for the PCM.
6. If any PCM DTCs retrieved, and are related to the concern, go to the Powertrain Control Module (PCM) Diagnostic Trouble Code Index to continue diagnostics. With Electronic Climate Control
7. If no DTCs related to the concern are retrieved, go to the Symptom Chart to continue diagnostics. Manual Climate Control