Test Description

WARNING: This page is about a different car, the 2003 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

2. The A/C compressor relay output is disabled if engine coolant temperature is above 121°C (250°F).
3. Placing the mode switch in any position other than OFF, along with placing the air temperature control switch in a cold setting, activates A/C operation. For the purpose of this and future steps where A/C operation is necessary, bi-level mode is used for consistent testing.
6. The HVAC control module is inoperative when the module does not respond to any operator control requests to enable the A/C compressor. The blower motor may still operate independent of the A/C controls.

Fig 1: Diagnostic System Check Table (HVAC Compressor Clutch Does Not Engage) (Step 1-6)
Courtesy of GENERAL MOTORS CORP.

Fig 2: Diagnostic System Check Table (HVAC Compressor Clutch Does Not Engage) (Step 7-17)

Courtesy of GENERAL MOTORS CORP.

Fig 3: Diagnostic System Check Table (HVAC Compressor Clutch Does Not Engage) (Step 18-30)

Courtesy of GENERAL MOTORS CORP.

Fig 4: Diagnostic System Check Table (HVAC Compressor Clutch Does Not Engage) (Step 31-34)

Courtesy of GENERAL MOTORS CORP.