Page 780 of 5267
P1273-A/C CLUTCH CONTROL CIRCUIT 2 HIGH
For a complete wiring diagramRefer to Section 8W.
Page 781 of 5267

When Monitored:
With the ignition on. Battery voltage greater than 10 volts. A/C Switch on.
Set Condition:
A shorted high condition has been detected in the A/C Clutch Control outputcircuit by the TIPM. One Trip
Fault. Three good trips to turn off the MIL.
Possible Causes
(C3) A/C CLUTCH CONTROL OUTPUT CIRCUIT SHORTED TO BATTERY VOLTAGE
EXCESSIVE RESISTANCE IN THE (Z153) A/C CLUTCH GROUND CIRCUIT
A/C COMPRESSOR CLUTCH
TIPM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.A/C CLUTCH OPERATION
Ignition on, engine not running.
With a scan tool under the PCM Actuators, actuate the A/C Clutch.
Is the A/C Clutch actuating?
Ye s>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
2.A/C CLUTCH CONTROL OPERATION FROM THE PCM
Turn the ignition off.
Disconnect the C2 TIPM harness connector.
Ignition on, engine not running.
Using the scan tool under the PCM Actuators, actuate the A/C Clutch.
With a 12-volt test light connected to ground, probe the (C13) A/C
Clutch Control circuit in the TIPM C2 harness connector.
Does the test light illuminate brightly and flash on an off?
Ye s>>
Go To 3
No>>
Perform the Diagnostic Procedure for P0645-A/C CLUTCH
CONTROL CIRCUIT. (Refer to 9 - ENGINE - DIAGNOSIS
AND TESTING)
Page 782 of 5267

3.(C3) A/C CLUTCH CONTROL OUTPUT CIRCUIT SHORTED TO BATTERY VOLTAGE
Turn the ignition off
Disconnect the C9 TIPM harness connector.
Disconnect the A/C Compressor Clutch harness connector.
Ignition on, engine not running.
Measure the voltage on the (C3) A/C Clutch Control Output circuit at the
A/C Compressor Clutch harness connector.
Is any voltage present?
Ye s>>
Repair the short to battery voltage in the (C3) A/C Clutch
Control Output circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
4.A/C CLUTCH GROUND CIRCUIT OPEN
Turn the ignition off.
Connect the C2 and C9 TIPM harness connectors.
Using a 12-volt test light connected to 12-volts, probe the (Z153) A/C
Clutch ground circuit at the A/C Compressor Clutch harness connector.
Does the test light illuminate brightly?
Ye s>>
Go To 5
No>>
Repair the excessive resistance in the (Z153) A/C Clutch
ground circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
5.A/C COMPRESSOR CLUTCH
Ignition on, engine not running.
Using the scan tool under the TIPM Actuators, actuate the A/C Clutch.
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.
Does the test light illuminate brightly and flash on and off?
Ye s>>
Replace the A/C Compressor Clutch per Service Informa-
tion.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 6
Page 784 of 5267
P1274-A/C CLUTCH CONTROL CIRCUIT 2 OPEN
For a complete wiring diagramRefer to Section 8W.
Page 785 of 5267

When Monitored:
With the ignition on. Battery voltage greater than 10.4 volts. TIPM requesting A/C Clutch operation.
Set Condition:
An open condition has been detected in the A/C Clutch Control Output circuit by the TIPM. One Trip Fault.
Three good trips to turn off the MIL.
Possible Causes
(C3) A/C CLUTCH CONTROL OUTPUT CIRCUIT OPEN
A/C CLUTCH
TIPM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.A/C CLUTCH OPERATION
Ignition on, engine not running.
With a scan tool under the PCM Actuators, actuate the A/C Clutch.
Is the A/C Clutch actuating?
Ye s>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
2.A/C CLUTCH CONTROL OPERATION FROM THE PCM
Turn the ignition off.
Disconnect the C2 TIPM harness connector.
Ignition on, engine not running.
Using the scan tool under the PCM Actuators, actuate the A/C Clutch.
With a 12-volt test light connected to ground, probe the (C13) A/C
Clutch Control circuit in the C2 TIPM harness connector.
Does the test light illuminate brightly and flash on an off?
Ye s>>
Go To 3
No>>
Perform the Diagnostic Procedure for P0645-A/C CLUTCH
CONTROL CIRCUIT. (Refer to 9 - ENGINE - DIAGNOSIS
AND TESTING)
Page 786 of 5267

3.(C3) A/C CLUTCH CONTROL OUTPUT CIRCUIT OPEN
Turn the ignition off
Disconnect the TIPM C9 harness connector.
Disconnect the A/C Clutch harness connector.
Measure the resistance of the (C3) A/C Clutch Control Output circuit
between the TIPM C9 harness connector and the A/C Clutch harness
connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 4
No>>
Repair the open in the (C3) A/C Clutch Control Output cir-
cuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
4.A/C CLUTCH
Connect the C2 and C9 TIPM harness connectors.
Ignition on, engine not running.
Using the scan tool under the TIPM Actuators, actuate the A/C Clutch.
With a 12-volt test light connected to ground, probe the (C3) A/C Clutch
Control Output circuit at the A/C Clutch harness connector.
Does the test light illuminate brightly and flash on and off?
Ye s>>
Replace the A/C Clutch in accordance with the Service
Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 5
Page 788 of 5267
P1275-A/C CLUTCH CONTROL CIRCUIT 2 OVERCURRENT
For a complete wiring diagramRefer to Section 8W.
Page 789 of 5267

When Monitored:
With the ignition on. Battery voltage greater than 10.4 volts. TIPM requesting A/C Clutch operation.
Set Condition:
An overcurrent condition is detected in the A/C Clutch control output circuit. One Trip Fault. Three good trips
to turn off the MIL.
Possible Causes
TERMINAL DAMAGE OR CORROSION
A/C CLUTCH GROUND HIGH RESISTANCE
(C3) A/C CLUTCH CONTROL OUTPUT CIRCUIT HIGH RESISTANCE
A/C COMPRESSOR CLUTCH
TIPM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.A/C CLUTCH OPERATION
Ignition on, engine not running.
With a scan tool in the TIPM Actuators, actuate the A/C Clutch.
Is the A/C Clutch actuating?
Ye s>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
2.VISUAL AND PHYSICAL CONNECTOR AND TERMINAL INSPECTION
Turn the ignition off.
Disconnect the TIPM C9 harness connector.
Disconnect the A/C Clutch harness connector.
Inspect the terminal and connector condition. Check for signs of corrosion build up or damage the would compro-
mise the terminal to controller pin connector.
NOTE: Make sure that all in-line connectors are inspected for corrosion and/or damage.
Visually inspect the wiring harness. Look for any chafed, pierced, pinched or partially broken wires hidden in the
wire insulation.
Were any of the above conditions found?
Ye s>>
Repair or replace as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3