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Home › Chrysler › 2007 › Pacifica Base, 3.8 L › Repair and Diagnosis › Engine Performance › System › DTCS P0645 To P1653 › P0645-A/C Control Circuit-Open › Diagnostic Test

Diagnostic Test

  1. 1) DTC IS ACTIVE 

    Ignition on, engine not running.

    With the scan tool, Clear DTCs in the Powertrain Control Module (PCM).

    With the scan tool, actuate the A/C Compressor Clutch Relay Control State.

    With the scan tool, select View DTCs.

    Is the status Active for this DTC? 

    Yes 

    1. Go to  2).

    No 

    1. Refer to *CHECKING FOR AN INTERMITTENT DTC .
  2. 2) INTERNAL FUSED B(+) CIRCUIT OPEN OR HIGH RESISTANCE 
    Fig 1: Checking The Internal Fused Ignition Switch Output (Run-Start) Circuit In The A/C Clutch Relay Connector Using A 12 Volt Test Light Connected To Ground
    GC0049657Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Remove the A/C Clutch Relay.

    Turn the ignition on.

    Using a 12 volt test light connected to ground, check the Internal Fused B(+) circuit in the A/C Clutch Relay connector.

    NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.

    Is the test light illuminated and bright? 

    Yes 

    1. Go to  3).

    No 

    1. Repair the Internal Fused B(+) circuit for an open circuit or high resistance.
    2. Perform PCM VERIFICATION TEST .
  3. 3) INTERNAL FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT OPEN OR HIGH RESISTANCE 
    Fig 2: Checking The Internal Fused Ignition Switch Output (Run-Start) Circuit In The A/C Clutch Relay Connector Using A 12 Volt Test Light Connected To Ground
    GC0049657Courtesy of CHRYSLER LLC

    Using a 12 volt test light connected to ground, check the Internal Fused Ignition Switch Output (Run-Start) circuit in the A/C Clutch Relay connector.

    NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.

    Is the test light illuminated and bright? 

    Yes 

    1. Go to  4).

    No 

    1. Repair the Internal Fused Ignition Switch Output (Run-Start) circuit for an open circuit or high resistance.
    2. Perform PCM VERIFICATION TEST .
  4. 4) (C13) A/C CLUTCH RELAY CONTROL CIRCUIT SHORTED TO VOLTAGE 
    Fig 3: Measuring The Voltage Of The A/C Clutch Relay Control Circuit In The A/C Clutch Relay Connector
    GC0049658Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the Powertrain Control Module (PCM) connector.

    Turn the ignition on.

    Measure the voltage of the (C13) A/C Clutch Relay Control circuit in the A/C Clutch Relay connector.

    Is there any voltage present? 

    Yes 

    1. Repair the (C13) A/C Clutch Relay Control circuit for a short to voltage.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Go to  5).
  5. 5) (C13) A/C CLUTCH RELAY CONTROL CIRCUIT SHORTED TO GROUND 
    Fig 4: Measuring The Resistance Between Ground And The A/C Clutch Relay Control Circuit In The A/C Clutch Relay Connector
    GC0049659Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Measure the resistance between ground and the (C13) A/C Clutch Relay Control circuit in the A/C Clutch Relay connector.

    Is the resistance below 100 ohms? 

    Yes 

    1. Repair the (C13) A/C Clutch Relay Control circuit for a short to ground.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Go to  6).
  6. 6) (C13) A/C CLUTCH RELAY CONTROL CIRCUIT OPEN OR HIGH RESISTANCE 
    Fig 5: Measuring The Resistance Of The A/C Clutch Relay Control Circuit Between The A/C Clutch Relay Connector And The Powertrain Control Module Harness Connector
    GC0049660Courtesy of CHRYSLER LLC

    Measure the resistance of the (C13) A/C Clutch Relay Control circuit between the A/C Clutch Relay connector and the Powertrain Control Module (PCM) harness connector.

    Is the resistance below 5.0 ohms? 

    Yes 

    1. Go to  7).

    No 

    1. Repair the (C13) A/C Clutch Relay Control circuit for an open circuit or high resistance.
    2. Perform PCM VERIFICATION TEST .
  7. 7) A/C CLUTCH RELAY 
    Fig 6: Checking The A/C Clutch Relay Control Circuit In The A/C Clutch Relay Harness Connector Using A 12 Volt Test Light Connected To 12 Volts
    GC0049661Courtesy of CHRYSLER LLC

    Connect the Powertrain Control Module (PCM) connector.

    Turn the ignition on.

    With the scan tool, actuate the A/C Compressor Clutch Relay Control State control to the ON position.

    Using a 12 volt test light connected to 12 volts, check the (C13) A/C Clutch Relay Control circuit in the A/C Clutch Relay harness connector.

    NOTE: If the DTC is active, the actuation test may not be allowed by the PCM. If may be necessary to clear the DTCs before starting the actuation.
    NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.

    Is the test light illuminated and bright? 

    Yes 

    1. Replace the A/C Clutch Relay in accordance with the Service Information.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Go to  8).
  8. 8) POWERTRAIN CONTROL MODULE (PCM) 

    Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the A/C Clutch Relay and the Powertrain Control Module (PCM).

    Look for any chafed, pierced, pinched, or partially broken wires.

    Look for broken, bent, pushed out or corroded terminals.

    Refer to any Technical Service Bulletins that may apply.

    Were any problems found? 

    Yes 

    1. Repair as necessary.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
    2. Perform PCM VERIFICATION TEST .
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