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Home >> Chrysler >> 2011 >> 300 C, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 90 ((Powertrain Control Module (Pcm) - Electrical Diagnostics - 68RFE Automatic Transmission)) >> Diagnosis and Testing >> P0868-Line Pressure Low >> Diagnostic Test

Diagnostic Test

WARNING: This page is about a different car, the 2011 RAM Pickup. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK FOR RELATED DTCS 
    1. With the scan tool, read and record all DTCs.

      Is the DTC P0933 present also?

      Yes 

      No 

      • Go To  2.
  2. CHECK THE Event Data 
    1. With the scan tool, read the DTC Event Data for the DTC P0868.

      Does the Line Pressure reading in the DTC Event Data show zero (0) psi?

      Yes 

      • Go To  3.

      No 

      • Go To  4.
  3. VERIFY PROPER LINE PRESSURE 
    1. With the scan tool, erase all DTCs.
    2. Start the vehicle in Park and raise engine speed to 1500 RPM.
    3. With the scan tool, compare the Line Pressure and Desired Line Pressure.

      Does the Line Pressure reading match the Desired Line Pressure reading (± 34.5 kPa or 5 psi)?

      Yes 

      • Disregard this DTC P0868. and follow the diagnostic procedure for any other DTCs which are present. Refer to Diagnosis and Testing  .

      No 

      • Go To  4.
  4. CHECK IF THE DTC IS CURRENT 
    1. With the scan tool, read DTCs.

      Is the status Active or is the Starts Since Set counter 2 or less for this DTC?

      Yes 

      • Go To  5.

      No 

      • Go To  15.
  5. CHECK THE LINE PRESSURE SENSOR CONNECTION 
    1. Ignition on, engine not running. 
    2. With the scan tool, monitor the Line Pressure while firmly pushing the Transmission Line Pressure Sensor connector inwards towards the Transmission.

      Did the Line Pressure reading on the scan tool CHANGE to about 207 kPa (30 psi) or 0.7 of a volt when the connector was pushed inward?

      Yes (value was higher and changed to 207 kPa (30 psi) or 0.7 of a volt) 

      • Disconnect and properly reconnect the Line Pressure Sensor connector. Inspect terminals and repair as necessary.
      • Perform the appropriate TRANSMISSION VERIFICATION TEST. Refer to 68RFE TRANSMISSION VERIFICATION TEST  .

      No (value is higher than 207 kPa (30 psi) or 0.7 of a volt and did not change or the value was already 207 kPa (30 psi) or 0.7 of a volt and did not change) 

      • Go To  6.
  6. CHECK THE PCM AND WIRING USING THE TRANSMISSION SIMULATOR 
    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 (special tool #8333A, Simulator, Transmission).
    4. With the Transmission Simulator select the "OFF" position on the "Input/Output Speed" switch.
    5. Ignition on, engine not running.
    6. With the scan tool, monitor the Line Pressure during the following steps.
    7. Using the Transmission Simulator, set the rotary knob to each of the three line pressure positions.
      NOTE:

      All three scan tool Line Pressure readings should be steady and ± 14 kPa (2.0 psi) or 0.1 of a volt of the reading specified on the Transmission Simulator.

      Did the Line Pressure read within ± 14 kPa (2.0 psi) or 0.1 of a volt in all three positions?

      Yes 

      • Go To  7.

      No 

      • Go To  11.
  7. CHECK THE LINE PRESSURE SENSOR 
    1. Turn the ignition off to the lock position.
    2. Disconnect the Transmission Simulator (special tool #8333A, Simulator, Transmission) and reconnect all previously disconnected connectors.
    3. Install the Line Pressure Adaptor (special tool #8259, Adapter, Pressure Test), and the Pressure Gauge (special tool #C-3293-SP, Gauge, Pressure 0-300 P.S.I.), 0 to 2000 kPa (0 to 300 psi).
    4. Start the engine in park.
    5. Monitor the line pressure readings of both the scan tool and the pressure gauge and compare the two readings.

      Is the line pressure gauge reading within 34 kPa (5 psi) of the scan tool reading?

      Yes 

      • Go To  8.

      No 

      • Replace the Line Pressure Sensor in accordance with the Service Information.
      • Perform the appropriate TRANSMISSION VERIFICATION TEST. Refer to 68RFE TRANSMISSION VERIFICATION TEST  .
  8. CHECK FOR PROPER LINE PRESSURE 
    1. With the vehicle still in Park, raise the engine speed to 1500 RPM.
    2. Compare line pressure readings of both the scan tool and the pressure gauge to the Desired Line Pressure reading on the scan tool.

      Is the Line Pressure gauge and scan tool reading within 34 kPa (5 psi) of the Desired Line Pressure scan tool reading?

      Yes 

      • Go To  15.

      No 

      • Go To  9.
  9. CHECK THE DEFAULT LINE PRESSURE 
    1. Turn the ignition off to the lock position.
    2. Disconnect the Transmission Solenoid/TRS Assembly harness connector.
      NOTE:

      Disconnection of the Transmission Solenoid/TRS Assembly harness connector may set several DTCs in the following steps. Disregard and erase any DTCs that set due to the disconnection.

    3. Start the engine.
    4. With the vehicle still in Park, raise the engine speed to 1500 RPM while monitoring the line pressure on the pressure gauge and record your findings.

      Was the gauge reading greater than 130 psi?

      Yes 

      • Go To  14.

      No 

      • Go To  10.
  10. CHECK FOR A PLUGGED TRANSMISSION OIL FILTER 
    1. Turn the ignition off to the lock position.
    2. Remove and inspect the Transmission Oil Pan for excessive debris in accordance with the Service Information.
    3. Remove and inspect the Primary Oil Filter in accordance with the Service Information.
      NOTE:

      Make sure the Primary Transmission Oil Filter and/or O-ring is not cracked or split.

      Does the Oil Pan contain excessive debris and/or is the Primary Oil Filter cracked or plugged?

      Yes 

      • Repair the plugged, cracked, or split Primary Transmission Oil Filter and/or O-ring. If the Primary Transmission Oil Filter is plugged refer to the Service Information for the proper Hydraulic repair procedure.
      • Perform the appropriate TRANSMISSION VERIFICATION TEST. Refer to 68RFE TRANSMISSION VERIFICATION TEST  .

      No 

      • Repair internal transmission and inspect the Transmission Oil Pump in accordance with the Service Information and replace if necessary. If no problem is found, replace the Solenoid/TRS Assembly.
      • Perform the appropriate TRANSMISSION VERIFICATION TEST. Refer to 68RFE TRANSMISSION VERIFICATION TEST  .
  11. CHECK THE (F856) 5-VOLT SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE 
    Fig 1: Measuring Voltage Of 5-Volt Supply Circuit For Short
    GC0111738Courtesy of CHRYSLER LLC
    1. Disconnect the Transmission Simulator (special tool #8333A, Simulator, Transmission).
    2. Reconnect all previously disconnected connectors except the Line Pressure Sensor harness connector.
    3. Ignition on, engine not running.
    4. Measure the voltage of the (F856) 5-volt Supply circuit in the Line Pressure Sensor harness connector.

      Is the voltage above 5.5 volts?

      Yes 

      No 

      • Go To  12.
  12. CHECK THE (F856) 5-VOLT SUPPLY CIRCUIT FOR AN OPEN 
    Fig 2: Checking 5-Volt Supply Circuit For Open
    GC0137257Courtesy of CHRYSLER LLC
    1. Turn the ignition off to the lock position.
    2. Disconnect the PCM C2 harness connector.
    3. Measure the resistance of the (F856) 5-volt Supply circuit between the Line Pressure Sensor harness connector and the appropriate terminal of the PCM C2 harness connector.

      Is the resistance above 5.0 Ohms?

      Yes 

      No 

      • Go To  13.
  13. CHECK THE (F856) 5-VOLT SUPPLY CIRCUIT FOR A SHORT TO GROUND 
    Fig 3: Checking 5-Volt Supply Circuit For Short To Ground
    GC0137258Courtesy of CHRYSLER LLC
    1. Measure the resistance between ground and the (F856) 5-volt Supply circuit.

      Is the resistance below 5.0 Ohms?

      Yes 

      No 

      • Go To  14.
  14. CHECK THE (T118) PRESSURE CONTROL SOLENOID CONTROL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT 
    Fig 4: Measuring Resistance Between Pressure Control Solenoid Control Circuit & All Other Circuits In Transmission Solenoid/TRS Assembly Harness Connector
    GC0111739Courtesy of CHRYSLER LLC
    1. Turn the ignition off to the lock position.
    2. Disconnect the Transmission Solenoid/TRS Assembly harness connector.
    3. Disconnect all PCM harness connectors.
    4. Measure the resistance between the (T118) Pressure Control Solenoid Control circuit and all other circuits in the Transmission Solenoid/TRS Assembly harness connector.

      Is the resistance below 5.0 Ohms between the (T118) Pressure Control Solenoid Control circuit and any other circuit(s) in the Transmission Solenoid/TRS Assembly harness connector?

      Yes 

      • Repair the (T118) Pressure Control Solenoid Control circuit for a short to another circuit(s).
      • Perform the appropriate TRANSMISSION VERIFICATION TEST. Refer to 68RFE TRANSMISSION VERIFICATION TEST  .

      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 the PCM in accordance with the Service Information. With the scan tool, perform Quick Learn.
      • Perform the appropriate TRANSMISSION VERIFICATION TEST. Refer to 68RFE TRANSMISSION VERIFICATION TEST  .
  15. 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.