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 Symptoms - HVAC Systems - Manual

1. Start the engine.
2. Place the blower motor switch in the OFF position.
3. Place the A/C request 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 a scan tool, observe the A/C Request parameter in the Engine Data 1 list.

Does the scan tool indicate that the A/C Request parameter is YES?

a

Go to Step 4

Go to Step 6

4

Test all the A/C request signal circuits for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 5

1. Turn OFF the ignition.
2. Disconnect the A/C high pressure switch.
3. Start the engine.
4. With a scan tool, observe the A/C Request parameter.

Does the scan tool indicate that the A/C Request parameter is YES?

Go to Step 12

Go to Step 11

Remove the A/C compressor clutch relay.

Does the A/C compressor clutch turn OFF?

Go to Step 7

Go to Step 9

Measure the resistance between the switch side of the relay terminals of the A/C compressor clutch relay.

Does the resistance measurement equal the specified value?

Go to Step 8

Go to Step 10

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

Did you find and correct the condition?

Go to Step 17

Go to Step 12

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

Did you find and correct the condition?

Go to Step 17

Go to Step 14

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

Did you find and correct the condition?

Go to Step 17

Go to Step 13

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

Did you find and correct the condition?

Go to Step 17

Go to Step 15

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

Did you find and correct the condition?

Go to Step 17

Go to Step 16

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 17

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

Did you complete the replacement?

Go to Step 17

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Replace the HVAC control assembly. Refer to Heater and Air Conditioning Control Replacement .

Did you complete the replacement?

Go to Step 17

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Important: Program the PCM.

Replace the PCM. Refer to one of the following procedures:

Did you complete the replacement?

Go to Step 17

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3