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Test Description

WARNING: This page is about a different car, the 2004 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.

  1. 3:  Verifies the condition is present.
  2. 4:  Determines if the A/C compressor clutch relay is at fault.
  3. 5:  Determines if the PCM is at fault or the A/C compressor clutch supply voltage circuit is at fault.
  4. 7:  Perform the recalibration procedure for the PCM.
DTC P1539

Step Action Yes No
Schematic Reference: HVAC Schematics 
Connector End View Reference: HVAC Connector End Views 
1 Did you perform the HVAC Diagnostic System Check? Go to Step 2  Go to Diagnostic System Check - HVAC Systems - Automatic 
2
IMPORTANT: Diagnose P0645 first if it is set.
  1. Install a scan tool.
  2. Start the engine.
  3. Turn OFF the A/C and let the engine idle.
  4. With a scan tool, observe the A/C Request Signal and the A/C Relay Command parameters in the Powertrain, Engine Data 2 list.
Does the A/C Request Signal display YES and the A/C Relay Command display ON when the A/C is not requested?		 Go to HVAC Compressor Clutch Does Not Engage  or HVAC Compressor Clutch Does Not Disengage  Go to Step 3 
3  With a scan tool, observe the A/C Clutch Feedback Signal parameter in the Powertrain, Engine Data 2 list.
Does the A/C Clutch Feedback Signal parameter display ON?		 Go to Step 4  Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
4  Remove the A/C compressor clutch relay.
Does the A/C Clutch Feedback Signal parameter display OFF?		 Go to Step 6  Go to Step 5 
5  Test the A/C compressor clutch supply voltage 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 8  Go to Step 7 
6 Replace the A/C compressor clutch relay.
Did you complete the replacement?		 Go to Step 8  -
7 
IMPORTANT: Perform the recalibration procedure for the PCM.
Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls.Did you complete the replacement?		 Go to Step 8  -
8
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?		 Go to Step 2  System OK
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