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Home >> Jeep >> 2007 >> Commander Base, 4.7 P, AWD >> Repair and Diagnosis >> Engine Performance >> System >> DTCS P0175 To P0315 >> P0298-Engine Oil Temperature Too High >> Diagnostic Test
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Diagnostic Test

  1. 1) DTC IS ACTIVE 
    NOTE: Diagnose any CAN - C Communication DTCs before continuing.

    Turn the ignition off.

    If possible, allow the vehicle to sit with the ignition off for more than 60 minutes in an environment where the temperature will allow the oil temperature to cool down.

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

    With a scan tool, select View DTCs.

    Is the status Active or Pending for this DTC? 

    Yes 

    1. Go to  2).

    No 

    1. Refer to INTERMITTENT CONDITION Diagnostic Procedure.
  2. 2) ENGINE OIL 

    The following conditions must be checked.

    • OEM recommended oil viscosity is being used.
    • Customer is following the oil change schedule.
    • Check the engine oil for contamination. (i.e, fuel and/or engine coolant)
    • Internal engine condition that may effect oil pressure.

    Were any of the above conditions found? 

    Yes 

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

    No 

    1. Go to  3).
  3. 3) ENGINE OIL TEMPERATURE SENSOR VOLTAGE 

    Turn the ignition off.

    Disconnect the Engine Oil Temperature Sensor harness connector.

    Turn the ignition on.

    With a scan tool, read the Engine Oil Temperature Sensor 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. Go to  4).

    No 

    1. Go to  5).
  4. 4) ENGINE OIL TEMPERATURE SENSOR 
    Fig 1: Checking Oil Temperature Sensor Signal Circuit & Ground Circuit
    GC0014854Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Connect a jumper wire between the (G224) EOT Signal circuit and the (K900) Sensor Ground circuit in the Engine Oil Temperature Sensor harness connector.

    Turn the ignition on.

    With a scan tool, read the Engine Oil Temperature Sensor voltage.

    NOTE: The sensor voltage should be approximately 0.0 volts (plus or minus .1 volt) with the jumper wire in place.

    Does the scan tool display the voltage as described above? 

    Yes 

    1. Replace the Engine Oil Temperature Sensor.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  5).
  5. 5) (G224) EOT SIGNAL CIRCUIT HIGH RESISTANCE 
    Fig 2: Checking Engine Oil Temperature Sensor Signal Circuit For High Resistance
    GC0050916Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Connect the Engine Oil Temperature Sensor 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 Miller Special Tool #8815 along with the #8815-1 to perform the diagnosis.

    Using a voltmeter, perform a voltage drop test by backprobing the (G224) EOT Signal circuit at the Engine Oil Temperature Sensor harness connector and probing the appropriate terminal of the special tool #8815. Make sure the voltmeter leads are connected so that positive polarity is displayed on the voltmeter.

    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.

    Start the engine.

    Is the voltage below 0.5 volts? 

    Yes 

    1. Go to  6).

    No 

    1. Repair the (G224) EOT Signal circuit for high resistance.
    2. Perform POWERTRAIN VERIFICATION TEST .
  6. 6) (K900) SENSOR GROUND CIRCUIT HIGH RESISTANCE 
    Fig 3: Checking Engine Oil Temperature Sensor Ground Circuit For High Resistance
    GC0050917Courtesy of CHRYSLER LLC

    Turn the ignition off.

    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 Miller Special Tool #8815 along with the #8815-1 to perform the diagnosis.

    Using a voltmeter, perform a voltage drop test by backprobing the (K900) Sensor Ground circuit at the Engine Oil Temperature Sensor harness connector and probing the appropriate terminal of the special tool #8815. Make sure the voltmeter leads are connected so that positive polarity is displayed on the voltmeter.

    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.

    Start the engine.

    Is the voltage below 0.5 volts? 

    Yes 

    1. Go to  7).

    No 

    1. Repair the (K900) Sensor Ground circuit for high resistance.
    2. Perform POWERTRAIN VERIFICATION TEST .
  7. 7) POWERTRAIN CONTROL MODULE (PCM) 

    Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Engine Oil Temperature Sensor 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.

    Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.

    Look for the data to change or for the DTC to reset during the wiggle test.

    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 Powertrain Control Module (PCM) in accordance with the Service Information.
    2. Perform POWERTRAIN VERIFICATION TEST .
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