Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Jeep >> 2008 >> Liberty Limited, 4WD, Part Time >> Repair and Diagnosis >> Engine Performance >> System >> DTCS P0420 To P0563 >> P0532-A/C Pressure Sensor Circuit Low >> Diagnostic Test

Diagnostic Test

  1. ACTIVE DTC 
    NOTE: Diagnose any CAN - C Communication DTCs before continuing.
    NOTE: Make sure the A/C refrigerant System is properly charged per Service Information.

    Start the engine and allow it to reach normal operating temperature.

    WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.
    NOTE: Diagnose and repair any system voltage or sensor supply voltage DTCs before continuing with this test.

    With the scan tool, select View DTCs.

    Is the DTC Active at this time? 

    Yes 

    1. Go To  2.

    No 

    1. Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
  2. (C818) 5-VOLT SUPPLY CIRCUIT 
    Fig 1: Measuring The Voltage On The 5-Volt Supply Circuit In The A/C Pressure Transducer Harness Connector
    GC0070766Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the A/C Pressure Transducer harness connector.

    Ignition on, engine not running.

    Measure the voltage on the (C818) 5-volt Supply circuit in the A/C Pressure Transducer harness connector.

    Is the voltage between 4.5 to 5.2 volts? 

    Yes 

    1. Go To  3.

    No 

    1. Go To  7.
  3. (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO GROUND 
    Fig 2: Measuring The Resistance Between Ground And The (C18) A/C Pressure Signal Circuit In The A/C Pressure Transducer Harness Connector
    GC0070767Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the C1 TIPM harness connector.

    Measure the resistance between ground and the (C18) A/C Pressure Signal circuit in the A/C Pressure Transducer harness connector.

    Is the resistance below 100 ohms? 

    Yes 

    1. Repair the short to ground in the (C18) A/C Pressure Signal circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go To  4.
  4. (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO THE (C918) SENSOR GROUND CIRCUIT 
    Fig 3: Measuring The Resistance Between The A/C Pressure Signal Circuit And The Sensor Ground Circuit In The A/C Pressure Transducer Harness Connector
    GC0070768Courtesy of CHRYSLER LLC

    Measure the resistance between the (C18) A/C Pressure Signal circuit and the (C918) Sensor Ground circuit in the A/C Pressure Transducer harness connector.

    Is the resistance below 100 ohms? 

    Yes 

    1. Repair the short between the (C918) Sensor Ground circuit and the (C18) A/C Pressure Signal circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go To  5.
  5. (C18) A/C PRESSURE SIGNAL CIRCUIT OPEN 
    Fig 4: Measuring The Resistance Of The A/C Pressure Signal Circuit From The A/C Pressure Transducer Harness Connector To C1 TIPM Harness Connector
    GC0070769Courtesy of CHRYSLER LLC

    Measure the resistance of the (C18) A/C Pressure Signal circuit from the A/C Pressure Transducer harness connector to C1 TIPM harness connector.

    Is the resistance below 5.0 ohms? 

    Yes 

    1. Go To  6.

    No 

    1. Repair the excessive resistance in the (C18) A/C Pressure Signal circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .
  6. A/C PRESSURE TRANSDUCER 

    Connect the C1 TIPM harness connector.

    Turn the ignition on.

    With the scan tool, monitor the A/C Pressure Transducer voltage.

    NOTE: The sensor voltage should be approximately 5.0 volts (plus or minus.1 volt) with the connector disconnected.

    Does the scan tool display the voltage as described above? 

    Yes 

    1. Verify that there is good pin to terminal contact in the A/C Pressure Transducer and the Powertrain Control Module connectors. If OK, replace the A/C Pressure Transducer.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go To  9.
  7. (C818) 5-VOLT SUPPLY CIRCUIT OPEN 
    Fig 5: Measuring The Resistance Of The 5-Volt Supply Circuit From The A/C Pressure Transducer Harness Connector To The C1 TIPM Harness Connector
    GC0070770Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the C1 TIPM harness connector.

    Measure the resistance of the (C818) 5-volt Supply circuit from the A/C Pressure Transducer harness connector to the C1 TIPM harness connector.

    Is the resistance below 5.0 ohms? 

    Yes 

    1. Go To  8.

    No 

    1. Repair the open in the (C818) 5-volt Supply circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .
  8. (C818) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND 
    Fig 6: Measuring The Resistance Between Ground And The 5-Volt Supply Circuit In The A/C Pressure Transducer Harness Connector
    GC0070771Courtesy of CHRYSLER LLC

    Measure the resistance between ground and the (C818) 5-volt Supply circuit in the A/C Pressure Transducer harness connector.

    Is the resistance below 100 ohms? 

    Yes 

    1. Repair the short to ground in the (C818) 5-volt Supply circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go To  9.
  9. TOTALLY INTEGRATED POWER MODULE 

    Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the related A/C Pressure Transducer and the Totally Integrated Power Module (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 Pressure Transducer and the Totally Integrated Power Module connectors.

    Refer to any Technical Service Bulletins that may apply.

    Were any problems found? 

    Yes 

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

    No 

    1. Replace the Totally Integrated Power Module per Service Information.
    2. Perform BODY VERIFICATION TEST - VER 1 .
scientia non olet · About Mike's Workshop Manuals