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Home >> Jeep >> 2009 >> Wrangler X, Standard >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 4 ((Transmission Control Module (TCM) - Electrical Diagnostics)) >> DTC Troubleshooting >> P0934-Line Pressure Sensor Circuit Low >> Diagnostic Test

Diagnostic Test

WARNING: This page is about a different variant/trim than selected.
  1. CHECK IF DTC IS CURRENT 
    1. With the scan tool, check the Starts Since Set counter for P0934.
      NOTE: This counter only applies to the last DTC set.

      Is the Starts Since Set counter 2 or less?

      Yes 

      • Go to step  2

      No 

      • Go to step  7
  2. CHECK THE PCM AND WIRING 
    1. Turn the ignition off to the lock position.
    2. Remove the Ignition Switch Feed fuse from the TIPM.
      CAUTION: Removal of the Ignition Switch Feed fuse from the TIPM will prevent the vehicle from being started in gear.
      WARNING: The Ignition Switch Feed fuse must be removed from the TIPM. Failure to do so can result in possible serious or fatal injury.
    3. Install the Transmission Simulator 8333.
    4. Ignition on, engine not running.
    5. With the scan tool, under Transmission Sensors, monitor the Line Pressure.
    6. Using the Transmission Simulator, set the rotary switch to each of the three line pressure positions.
      NOTE: The readings should be within ±14 kPa (2.0 psi) on the scan tool to the pressure readings specified on Transmission Simulator.

      Does the Line Pressure on the scan tool match the line pressures on the Transmission Simulator?

      Yes 

      No 

      • Go to step  3
  3. CHECK THE (T38) LINE PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND 
    Fig 1: Checking Line Pressure Sensor Signal Circuit
    GC0111748Courtesy of CHRYSLER LLC
    1. Turn the ignition off to the lock position.
    2. Disconnect the PCM C4 harness connector and connect the PCM Pinout Box 8815.
    3. Disconnect the Transmission Simulator 8333.
      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 the PCM Pinout Box 8815 to perform diagnosis.
    4. Measure the resistance between ground and the (T38) Line Pressure Sensor Signal circuit.

      Is the resistance below 5.0 Ohms?

      Yes 

      No 

      • Go to step  4
  4. CHECK THE (T38) LINE PRESSURE SENSOR SIGNAL CIRCUIT FOR AN OPEN 
    Fig 2: Checking Line Pressure Sensor Signal Circuit
    GC0111749Courtesy of CHRYSLER LLC
    1. Disconnect the PCM C4 harness connector and connect the PCM Pinout Box 8815.
    2. Measure the resistance of the (T38) Line Pressure Sensor Signal circuit between the Line Pressure Sensor harness connector and the appropriate terminal of the PCM Pinout Box 8815.

      Is the resistance above 5.0 Ohms?

      Yes 

      No 

      • Go to step  5
  5. CHECK THE (F856) 5-VOLT SUPPLY CIRCUIT FOR AN OPEN 
    Fig 3: Checking 5-Volt Supply Circuit
    GC0111733Courtesy of CHRYSLER LLC
    1. Disconnect the PCM C1 harness connector and connect the PCM Pinout Box 8815.
    2. Measure the resistance of the (F856) 5-volt Supply circuit between the Line Pressure sensor harness connector and the appropriate terminal of the PCM Pinout Box 8815.

      Is the resistance below 5.0 Ohms?

      Yes 

      No 

      • Go to step  6
  6. CHECK THE (F856) 5-VOLT SUPPLY CIRCUIT FOR A SHORT TO GROUND 
    Fig 4: Checking 5-Volt Supply Circuit
    GC0111734Courtesy of CHRYSLER LLC
    1. Disconnect the PCM C1 harness connector and connect the PCM Pinout Box 8815.
    2. Measure the resistance between ground and the (F856) 5-volt Supply circuit.

      Is the resistance below 5.0 Ohms?

      Yes 

      No 

      • Using the schematics as a guide, check the Powertrain Control Module (PCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace and program the PCM in accordance with the Service Information. With the scan tool, perform Quick Learn.
      • Perform the 545RFE TRANSMISSION VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Transmission Control (TCM) - Standard Procedure .
  7. CHECK THE WIRING AND CONNECTORS 
    1. The conditions necessary to set this DTC are not present at this time.
    2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
    3. Wiggle the wires while checking for shorted and open circuits.
    4. With the scan tool, check the Event Data to help identify the conditions in which the DTC was set.

      Where there any problems found?

      Yes 

      No 

      • Test Complete.