AC Control Panel - Diagnostic Procedure

82-23

A/C Control Panel - Diagnostic Procedure

MODEL:
88-91 MY Sedans

DATE: 6/91

ISSUE:

Unnecessary replacement of A/C control panel due to mis-diagnosis of the A/C system.

ACTION:

Diagnose control panel faults before replacing any part. Refer to the following information:

Control Panel "Lock-up". Refer to Technical Bulletin 82-22.

Temperature Instability. Refer to Technical Bulletin 82-21.














If a feature or component does not function, perform a manual System function check. See illustrations.

If the A/C system responds correctly for each step, No fault exists OR it is intermittent. Review complaint and system operation with the customer.

NOTE:
Allow at least 15 seconds after each STEP for the control system to stabilize.

The engine must be idling and be at normal operating temperature.

Complete all actions for each STEP before noting SYSTEM RESPONSE.

Diagnostic Information

Vacuum System - Leaks, blocked or kinked hoses, refer to 1991 Model Year Sedan Range Update (S-69), pg. 38-40.

Operation of solenoid valves, check signal voltages. Use appropriate Model Year Electrical Guide.

Flaps, Flat and Rotary - Check flaps for free movement, sealing, and operation of vacuum actuator or motor.

Electrical Components - Check circuit and signal voltages. Use JDS and appropriate Model Year Electrical Guide.