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Home >> Jeep >> 2009 >> Commander Overland, RWD >> Repair and Diagnosis >> Transmission >> Automatic Trans >> (Powertrain Control Module (Pcm) - Electrical Diagnostics - 545RFE Automatic Transmission) >> DTC Troubleshooting >> P0846-2C Pressure Switch Rationality >> Diagnostic Test

Diagnostic Test

  1. DETERMINE IF RELATED TCM POWER INPUT DTCS ARE PRESENT 
    1. Using the scan tool, check for other transmission DTCs.

      Are there any TCM Power Input DTCs present also?

      Yes 

      No 

      • Go to step  2
  2. CHECK IF THE DTC IS CURRENT 
    1. Using the scan tool, check the Event Data.

      Does the Event Data show data for DTC P0846?

      Yes 

      • Go to step  3

      No 

  3. CHECK FOR MULTIPLE DTCS 
    1. Using the scan tool, check for other transmission DTCs.

      Are there two or more related pressure switch rationality DTCs present in addition to P0846?

      Yes 

      • Go to step  4

      No 

      • Go to step  7
  4. CHECK IF ALL PRESSURE SWITCHES READ CLOSED 
    1. Using the scan tool, check the Event Data for P0846.
      NOTE: Make sure to record all Event Data stored in the scan tool for future reference in this test procedure.

      Do all the pressure switches read CLOSED in the Event Data for P0846?

      Yes 

      No 

      • Go to step  5
  5. CHECK IF ALL PRESSURE SWITCHES READ OPEN 

    In the Event Data recorded earlier, do all the pressure switches read OPEN?

    Yes 

    • Go to step  6

    No 

    • Go to step  7
  6. CHECK FOR LOW LINE PRESSURE 

    In the Event Data recorded earlier, is the Line Pressure less than 40 psi, and significantly below the Desired Line Pressure?

    Yes 

    • Repair as necessary to correct low line pressure. Check fluid level and adjust as necessary. If fluid level is OK, check the Primary Oil Filter seal for a split, crack, or improperly installed. If the filter and seal are OK, check the Main Regulator Valve in the Oil Pump. Refer to the appropriate Service Information for the above procedures.
    • Perform the 545RFE TRANSMISSION VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .

    No 

  7. CHECK IF THE DTC SET IN PARK REVERSE OR NEUTRAL 
    1. Using the scan tool, check the Event Data for P0846.
      NOTE: Make sure to record all Event Data stored in the scan tool for future reference in this test procedure.

      Does the Event Data show the DTC P0846 set in Park, Reverse, or Neutral?

      Yes 

      • Go to step  12

      No 

      • Go to step  8
  8. CHECK IF THE 2C PRESSURE SWITCH READS CLOSED 

    In the Event Data recorded earlier, does the Event Data show the 2C Pressure Switch reading CLOSED?

    Yes 

    • Go to step  10

    No 

    • Go to step  9
  9. COMPARE THE LINE PRESSURE TO THE DESIRED LINE PRESSURE 
    1. In the Event Data recorded earlier, compare the Line Pressure and the Desired Line Pressure.

      Is the Line Pressure less than 40 psi, and significantly below the Desired Line Pressure?

      Yes 

      • Repair as necessary to correct low line pressure. Check fluid level and adjust as necessary. If fluid level is OK, check the Primary Oil Filter seal for a split, crack, or improperly installed. If the filter and seal are OK, check the Main Regulator Valve in the Oil Pump. Refer to the appropriate Service Information for the above procedures.
      • Perform the 545RFE TRANSMISSION VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .

      No 

      • Go to step  15
  10. CHECK THE PCM AND WIRING 
    1. Turn the ignition off to the lock position.
    2. Remove the Starter Relay.
      CAUTION: Removal of the Starter Relay will prevent the vehicle from being started in gear.
      WARNING: The Starter Relay must be removed from the PDC. Failure to do so may result in possible serious or fatal injury.
      NOTE: Failure to remove the Starter Relay can cause a Transmission - No Response condition.
    3. Install the Transmission Simulator 8333.
    4. Ignition on, engine not running.
    5. With the Transmission Simulator, turn the Pressure Switch selector switch to the 2C position.
    6. Using the scan tool, monitor the 2C Pressure Switch while pressing the Pressure Switch test button on the Transmission Simulator.

      Did the state of the 2C Pressure Switch change while pressing the Pressure Switch Test button?

      Yes 

      • Go to step  11

      No 

      • Go to step  12
  11. CHECK THE TRANSMISSION SOLENOID/TRS ASSEMBLY 
    1. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
    2. Wiggle the wires while checking for shorted and open circuits.

      Where there any problems found?

      Yes 

      No 

  12. CHECK THE (T147) 2C PRESSURE SIGNAL CIRCUIT FOR AN OPEN 
    Fig 1: Checking 2C Pressure Signal Circuit For An Open
    GC0106927Courtesy of CHRYSLER LLC
    1. Turn the ignition off to the lock position.
    2. Disconnect the Transmission Simulator 8333.
    3. Disconnect the PCM C4 harness connector.
    4. Connect the PCM Pinout Box 8815 to the PCM C4 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 the PCM Pinout Box 8815 to perform diagnosis.
    5. Measure the resistance of the (T147) 2C Pressure Switch Sense circuit between the Transmission Solenoid/TRS Assembly harness connector and the appropriate terminal of the PCM Pinout Box 8815.

      Is the resistance above 5.0 Ohms?

      Yes 

      No 

      • Go to step  13
  13. CHECK THE (T147) 2C PRESSURE SIGNAL CIRCUIT FOR A SHORT TO GROUND 
    Fig 2: Checking 2C Pressure Signal Circuit For A Short To Ground
    GC0106928Courtesy of CHRYSLER LLC
    1. Measure the resistance between ground and the (T147) 2C Pressure Switch Sense circuit.

      Is the resistance below 5.0 Ohms?

      Yes 

      No 

      • Go to step  14
  14. CHECK THE (T147) 2C PRESSURE SIGNAL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT 
    Fig 3: Checking 2C Pressure Signal Circuit For A Short To Another Circuit
    GC0106926Courtesy of CHRYSLER LLC
    1. Measure the resistance between the (T147) 2C Pressure Switch Sense circuit and all the other circuits in the Transmission Solenoid/TRS Assembly harness connector.

      Is the resistance below 5.0 Ohms?

      Yes 

      No 

  15. CHECK IF THE NO. 5 AND/OR NO. 7 CHECK BALL IS CUT OR DAMAGED 
    1. Turn the Ignition off to the lock position.
    2. Remove the Valve Body Assembly in accordance with the Service Information.
    3. Inspect the No. 5 and No. 7 check balls for any cuts or damage.
    4. Check for an extra check ball in the passage downstream from the No. 7 check ball pocket.
    5. Inspect the 2C accumulator piston and seals and also the 2C tower seal on top of the valve body. Refer to the appropriate Service Information.

      Where there any problems found?

      Yes 

      No 

      • Go to step  16
  16. CHECK FOR EXCESSIVE FLUID LEAKAGE WITHIN 2C CLUTCH CIRCUIT 
    1. Air check the 2C Clutch hydraulic circuit. Refer to the appropriate Service Information.
      NOTE: This hydraulic clutch circuit contains a small bleed orifice. Small leakage is considered normal.

      Was there excessive air leakage in the 2C Clutch hydraulic circuit?

      Yes 

      No 

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