LEMON Manuals: Even more car manuals for everyone
Home >> Jeep >> 2009 >> Commander Overland, 4WD >> Repair and Diagnosis >> Engine Performance >> System >> DRIVEABILITY - Gas - Non-DTC Diagnostics >> Diagnosis And Testing >> Checking The Pcm Power And Ground Circuits >> Diagnostic Test

Diagnostic Test

  1. PCM WIRING OR CONNECTORS 
    1. Turn the ignition off.
    2. Using the wiring diagram/schematic as a guide, inspect the wiring and each connector at the PCM.
    3. Look for any chafed, pierced, pinched, or partially broken wires.
    4. Look for broken, bent, pushed out or corroded terminals.

      Were any problems found?

      Yes 

      No 

      • Go to step  2
  2. CHECKING THE PCM GROUND CIRCUITS 
    Fig 1: Checking PCM Ground Circuits For Open Circuit Or High Resistance
    GC0091376Courtesy of CHRYSLER LLC
    1. 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 PCM Pinout Box 8815 to perform diagnosis.
    2. Using a 12 volt test light connected to 12 volts, check the PCM ground circuits.
    3. Wiggle test each circuit during the test to check for an intermittent open in the circuit.
      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 

      • Go to step  3.

      No 

  3. CHECKING THE PCM FUSED IGNITION CIRCUITS 
    Fig 2: Checking PCM Fused Ignition Circuit For Open Or Short To Ground
    GC0090994Courtesy of CHRYSLER LLC
    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 PCM Pinout Box 8815 to perform diagnosis.
    1. Turn the ignition on.
    2. Using a 12 volt test light connected to ground, check the PCM Fused Ignition circuits.
    3. Check each circuit with the ignition on, engine running position, and during cranking.
    4. Wiggle test each circuit during the test to check for an intermittent open in the circuit.
      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 

      • Go to step  4.

      No 

  4. CHECKING THE PCM FUSED B+ CIRCUITS 
    Fig 3: Checking Fused B+ Circuit For Open Or Short To Ground
    GC0091377Courtesy of CHRYSLER LLC
    1. 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 PCM Pinout Box 8815 to perform diagnosis.
    2. Using a 12 volt test light connected to Ground, check the PCM Fused B+ circuits.
    3. Wiggle test each circuit during the test to check for an intermittent open in the circuit.
      NOTE: The test light should be illuminated and bright with the ignition on and not illuminated with the ignition off. Compare the brightness to that of a direct connection to the battery.

      Is the test light illuminated as described above?

      Yes 

      • Test complete.

      No