A/C Clutch Control Circuit 2 High
P1273 - A/C Clutch Control Circuit 2 High
For a complete wiring diagram, refer to.
Theory of Operation
The Totally Integrated Power Module (TIPM) is commanded by the Powertrain Control Module (PCM) through a hardwired signal to actuate the A/C Clutch. The TIPM actuates the A/C Clutch by providing voltage through a high-side driver circuit. The TIPM monitors this circuit for correct voltage and current flow.
• When Monitored: With the ignition on. Battery voltage greater than 10.4 volts. Air Conditioning (A/C) Switch on. A/C Compressor Clutch command on.
• Set Condition: The Totally Integrated Power Module (TIPM) detects the voltage on the A/C Clutch Driver circuit is higher than the calibrated level.
Test Step 1 - A/C CLUTCH OPERATION
• If Powertrain Control Module (PCM) DTC P0645-A/C CLUTCH CONTROL CIRCUIT is present, diagnose it first.
• Ignition on, engine not running.
• With the scan tool, actuate the A/C Clutch.
Does the A/C Clutch actuate?
Yes
• Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
No
• Go to Test Step 2
Test Step 2 - (C3) A/C CLUTCH DRIVER CIRCUIT SHORTED TO VOLTAGE
• Turn the ignition off.
• Disconnect the A/C Compressor Clutch harness connector.
• Disconnect the TIPM C1 harness connector.
• Ignition on, engine not running.
• Measure the voltage between ground and the (C3) A/C Clutch Driver 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 Driver circuit.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
No
• Go to Test Step 3
Test Step 3 - CHECK THE TIPM FOR CORRECT OPERATION
• Turn the ignition off.
• Reconnect the TIPM C1 harness connector.
• Ignition on, engine not running.
• Connect a 12-volt test light between the (C3) A/C Clutch Driver circuit and (Z803/Z903) Ground circuit at the A/C Compressor Clutch harness connector.
• With the scan tool, actuate the A/C Clutch.
Does the test light illuminate when the A/C Clutch is commanded on?
Yes
• Verify that there is good pin to terminal contact in the A/C Compressor Clutch and TIPM connectors. If OK, replace the A/C Clutch.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
No
• Go to Test Step 4
Test Step 4 - CHECK THE (C3) A/C CLUTCH DRIVER CIRCUIT FOR AN OPEN
• Turn the ignition off.
• Disconnect the TIPM C1 harness connector.
• Measure the resistance of the (C3) A/C Clutch Driver circuit between the A/C Compressor Clutch harness connector and the TIPM C1 harness connector.
Is the resistance below 5.0 Ohms?
Yes
• Go to Test Step 5
No
• Repair the open in the (C3) A/C Clutch Driver circuit.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
Test Step 5 - CHECK THE (Z803/Z903) GROUND CIRCUIT FOR AN OPEN
• Using a 12-volt test light connected to 12-volts, check the (Z803/Z903) Ground circuit at the A/C Compressor Clutch harness connector.
Does the test light illuminate brightly?
Yes
• Go to Test Step 6
No
• Repair the open or excessive resistance in the (Z803/Z903) Ground circuit.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
Test Step 6 - TOTALLY INTEGRATED POWER MODULE (TIPM)
• Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the A/C Clutch and TIPM.
• Look for any chafed, pierced, pinched, or partially broken wires.
• Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the A/C Compressor Clutch and TIPM connectors.
• Perform any Technical Service Bulletins that may apply.
Were there any problems found?
Yes
• Repair as necessary.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
No
• Replace the TIPM.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior