Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

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HOMESERVICE MANUALSJEEP2009WRANGLER UNLIMITED SAHARA, RWDREPAIR AND DIAGNOSIS (SINGLE PAGE)ACCESSORIES & EQUIPMENTCOMMUNICATION DEVICES(TOTALLY INTEGRATED POWER MODULE (TIPM) - ELECTRICAL DIAGNOSTICS)DTC TROUBLESHOOTINGP1273-A/C CLUTCH CONTROL CIRCUIT 2 HIGHDIAGNOSTIC TEST

2009 Jeep Wrangler Unlimited Sahara, RWD

Diagnostic Test

2009 Jeep Wrangler Unlimited Sahara, RWDSECTION Diagnostic Test

A/C CLUTCH OPERATION
NOTE: Diagnose and repair P0645 A/C CLUTCH CONTROL CIRCUIT OPEN before continuing.
1. Ignition on, engine not running.
2. With the scan tool actuate the A/C Clutch.
  Is the A/C Clutch actuating?
  
  Yes
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 2
A/C CLUTCH CONTROL OPERATION FROM THE PCM

Fig 1: Checking A/C Clutch Control Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the C3 PCM harness connector.
  CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install PCM Pinout Box 8815 along with the Adapter 8815-1 to perform the diagnosis.
3. Ignition on, engine not running.
4. With the scan tool actuate the A/C Clutch.
5. Measure the voltage between the appropriate terminal of the PCM Pinout Box 8815 and ground.
  Is the voltage below 1 volt?
  
  Yes
  - Go to step 3
  No
  - Perform the diagnostic procedure for P0645-A/C CLUTCH CONTROL CIRCUIT. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Diagnosis and Testing .
(C3) A/C CLUTCH CONTROL OUTPUT CIRCUIT SHORTED TO VOLTAGE

Fig 2: A/C Clutch Control Output Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the A/C Compressor Clutch harness connector.
3. Ignition on, engine not running.
4. Measure the voltage on the (C3) A/C Clutch Control Output circuit at the A/C Compressor Clutch harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the short to voltage in the (C3) A/C Clutch Control Output circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 4
A/C CLUTCH GROUND CIRCUIT OPEN

Fig 3: Checking A/C Clutch Ground Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Connect the C1 TIPM harness connector.
3. Using a 12-volt test light connected to 12 Volts, probe the (Z904) A/C Clutch ground circuit at the A/C Compressor Clutch harness connector.
  NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Does the test light illuminate brightly?
  
  Yes
  - Go to step 5
  No
  - Repair the excessive resistance in the (Z904) A/C Clutch ground circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
A/C COMPRESSOR CLUTCH

Fig 4: Checking A/C Clutch Control Output Circuit
Courtesy of CHRYSLER LLC
1. Ignition on, engine not running.
2. Using the scan tool actuate the A/C Clutch.
3. With a 12-volt test light connected to ground, probe the (C3) A/C Clutch Control Output circuit at the A/C Compressor Clutch harness connector.
  NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Does the test light illuminate accordingly during the actuation?
  
  Yes
  - Verify that there is good pin to terminal contact in the A/C Clutch, TIPM and Powertrain Control Module connectors. If OK, replace the A/C Compressor Clutch in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 6
TOTALLY INTEGRATED POWER MODULE (TIPM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the A/C Clutch, TIPM and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the A/C Clutch, TIPM and Powertrain Control Module connectors.
4. Perform any Technical Service Bulletins (TSBs) that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Replace the Totally Integrated Power Module in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure .

RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.