Schematic Reference: HVAC Schematics

DEFINITION: The A/C compressor clutch will not disengage when an A/C request has not been made and a Powertrain DTC has not been set.

Did you review the HVAC operation and perform the necessary inspections.

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Automatic

1. Start the engine.
2. Place the blower motor switch in the OFF position.
3. Place the A/C switch in the OFF position.

Does the A/C compressor operate?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

With the scan tool, observe the A/C commanded parameter in the Powertrain Data List.

Does the scan tool indicate the A/C commanded parameter is ON?

Go to Step 4

Go to Step 6

With the scan tool, observe the A/C Control Head (Desired) parameter in the DIM A/C Information List.

Does the scan tool display OFF?

Go to Step 5

Go to Step 11

With a scan tool, observe the A/C Clutch (Desired) parameter in the DIM A/C Information List.

Does the scan tool display OFF?

Go to Step 13

Go to Step 12

1. Turn OFF the ignition.
2. Disconnect the A/C compressor clutch relay.
3. Turn the ignition ON.

Does the A/C compressor clutch disengage?

Go to Step 7

Go to Step 8

Test the control circuit of the A/C compressor clutch relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 19

Go to Step 10

Test the A/C compressor clutch voltage supply circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 19

Go to Step 9

Inspect for poor connections at the harness connector of the A/C compressor clutch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 19

Go to Step 15

Inspect for poor connections at the A/C compressor clutch relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 19

Go to Step 14

Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 19

Go to Step 16

Inspect for poor connections at the dash integration module (DIM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 19

Go to Step 17

Inspect for poor connections at the harness connector of the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 19

Go to Step 18

Replace the A/C compressor clutch relay. Refer to Compressor Relay Replacement in Heating, Ventilation, and Air Conditioning.

Did you complete the replacement?

Go to Step 19

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Replace the A/C compressor clutch Hub and Plate. Refer to Compressor Clutch Plate and Hub Assembly Removal and Compressor Clutch Plate/Hub Assembly Install in Heating, Ventilation, and Air Conditioning.

Did you complete the replacement?

Go to Step 19

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Replace the HVAC control module. Refer to HVAC Control Module Replacement .

Did you complete the replacement?

Go to Step 19

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Replace the dash integration module (DIM). Refer to Dash Integration Module Replacement in Body Control Systems.

Did you complete the replacement?

Go to Step 19

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Important:  Perform the programming procedure for the PCM.

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 3.8L.

Did you complete the replacement?

Go to Step 19

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2