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Home >> Jeep >> 2020 >> Grand Cherokee Trackhawk >> Repair and Diagnosis >> External Pages >> Different car >> Section 273 (68RFE Automatic Transmission - DTCS P0875-00 To U1449-00 - 2500HD & 3500HD) >> DTC Troubleshooting >> P2761-00-Torque Converter Clutch Pressure Control Solenoid Control Circuit/Open >> Diagnostic Test

Diagnostic Test

WARNING: This page is about a different car, the 2019 RAM 3500 HD and 2019 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
  1. READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR DTC TO RETURN 
    1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
    2. With the scan tool, run a vehicle Scan Report, or record the Environmental Data related to the DTCs.
    3. With the scan tool, erase all DTCs.
    4. Turn the ignition off for a minimum of 10.0 seconds.
    5. Turn the ignition on.
    6. Using the recorded Environmental Data and the When Monitored Conditions above, operate the vehicle in the conditions that set the DTC.
    7. With the scan tool, read DTCs.

    Did the DTC return?

    Yes 

    • Go To  2

    No 

  2. RELATED TCM POWER INPUT DTCS PRESENT 
    1. With the scan tool, check DTCs.

      Are there any TCM Power Control Circuit or TCM Power Input DTCs present?

      Yes 

      • Perform the appropriate diagnostic procedure.

      No 

      • Go To  3
  3. ISOLATE AND CHECK THE (T125) TORQUE CONVERTER CLUTCH SOLENOID CONTROL CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    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 GPEC Diagnostic Adaptor to perform the diagnosis.

    1. Disconnect the (special tool #10436, Adapter, GPEC Diagnostic) and remove from the vehicle.
      1. The ignition must be off when checking the continuity of a circuit.
      2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and the component harness connector containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
      3. Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note:  The meter leads can add resistance to the measurement value.
      4. Connect one lead of the DVOM to the circuit being tested at the component harness connector.
      5. Connect the other lead to the circuit being tested at the GPEC Diagnostic Adapter and measure the resistance of the circuit.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  4

      No 

  4. ISOLATE AND CHECK THE (T125) TORQUE CONVERTER CLUTCH SOLENOID CONTROL CIRCUIT FOR A SHORT TO GROUND 
    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 GPEC Diagnostic Adaptor to perform the diagnosis.

    1. The ignition must be off when checking a circuit for continuity to ground.
    2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and every component harness connector containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
    3. Connect the negative lead of the DVOM to a known good ground.
    4. With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.
    NOTE:

    There should be no continuity between ground and the circuit being tested.

    Is there continuity between ground and the circuit being tested?

    Yes 

    • Repair the circuit for a short to ground. Use the wiring diagram as a guide to trace the circuit and look for any in-line connectors to help isolate the location of the short.
    • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

    No 

    • Go To  5
  5. ISOLATE AND CHECK THE INTERNAL TORQUE CONVERTER CLUTCH SOLENOID CONTROL HARNESS FOR AN OPEN/HIGH RESISTANCE 
    1. Remove the transmission oil pan.
      1. The ignition must be off when checking the continuity of a circuit.
      2. Isolate the circuit by disconnecting the transmission harness connector. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
      3. Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note:  The meter leads can add resistance to the measurement value.
      4. Connect one lead of the DVOM to the circuit being tested at the component harness connector.
      5. Connect the other lead to the circuit being tested at the transmission side of the transmission harness connector and measure the resistance of the circuit.
      NOTE:

      When probing a circuit at an Electronic Control Unit (ECU) harness connector, always use an appropriate back probing tool to prevent any possible damage to the ECU terminals.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  6

      No 

      • Repair or replace the internal harness as necessary for an open circuit or high resistance.
      • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .
  6. ISOLATE AND CHECK THE INTERNAL TORQUE CONVERTER CLUTCH SOLENOID CONTROL HARNESS FOR A SHORT TO GROUND 
    1. The ignition must be off when checking a circuit for continuity to ground.
    2. Isolate the circuit by disconnecting the transmission harness connector. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
    3. Connect the negative lead of the DVOM to a known good ground.
    4. With the positive lead of the DVOM, probe the wires at the TCC VFS harness connector and check for continuity between the circuit and ground.
    NOTE:

    There should be no continuity between ground and the circuit being tested.

    Is there continuity between ground and the circuit(s) being tested?

    Yes 

    • Repair or replace the internal harness as necessary for a short to ground.
    • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

    No 

    • Go To  7
  7. CHECK THE TORQUE CONVERTER CLUTCH SOLENOID FOR AN OPEN CIRCUIT OR HIGH RESISTANCE 
    1. Measure the resistance across the TCC VFS with DVOM.

      Is the resistance greater than 15 Ohms?

      Yes 

      NOTE:

      This transmission is equipped with a solenoid for the Torque Converter Clutch (TCC) that is a Variable Force Solenoid (VFS) with close tolerance Pressure/Inductance (PI) curve. It is necessary to update the TCC solenoid PI data in the PCM when replacing the TCC solenoid, Valve Body or Transmission assembly. This is done with the scan tool using the "Program Torque Converter Solenoid PI Curve" routine. The PI data is located on a 2-D BAR code etched on the body of the TCC solenoid. The data must be entered into the scan tool in order to upload the information to the PCM.

      When replacing the TCC solenoid or Valve Body, obtain the PI data before installing the transmission oil pan. When replacing the transmission, the PI data can be obtained from a 2-D bar code on the exterior of the new transmission. Early build transmissions will have the 2-D barcode label on the right side of the transmission case. Late build transmissions will have the label attached to a machined pad at the top of the case, near the rear of the transmission. If it is suspected that the valve body or TCC VFS has been replaced without uploading the correct PI data into the PCM, the transmission oil pan must be removed to retrieve the information from the 2-D bar code on the body of the TCC solenoid.

      • Replace the TCC solenoid in accordance with the Service Information.
      • If present, remove the external TCC VFS bar code label.
      • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

      No 

      • Go To  8
  8. CHECK THE TORQUE CONVERTER CLUTCH SOLENOID FOR A SHORT TO GROUND 
    1. Connect the negative lead of the DVOM to a known good ground.
    2. With the positive lead of the DVOM, carefully probe the pins in the TCC solenoid.

      Is there continuity to ground present?

      Yes 

      NOTE:

      This transmission is equipped with a solenoid for the Torque Converter Clutch (TCC) that is a Variable Force Solenoid (VFS) with close tolerance Pressure/Inductance (PI) curve. It is necessary to update the TCC solenoid PI data in the PCM when replacing the TCC solenoid, Valve Body or Transmission assembly. This is done with the scan tool using the "Program Torque Converter Solenoid PI Curve" routine. The PI data is located on a 2-D BAR code etched on the body of the TCC solenoid. The data must be entered into the scan tool in order to upload the information to the PCM.

      When replacing the TCC solenoid or Valve Body, obtain the PI data before installing the transmission oil pan. When replacing the transmission, the PI data can be obtained from a 2-D bar code on the exterior of the new transmission. Early build transmissions will have the 2-D barcode label on the right side of the transmission case. Late build transmissions will have the label attached to a machined pad at the top of the case, near the rear of the transmission. If it is suspected that the valve body or TCC VFS has been replaced without uploading the correct PI data into the PCM, the transmission oil pan must be removed to retrieve the information from the 2-D bar code on the body of the TCC solenoid.

      • Replace the TCC solenoid in accordance with the Service Information.
      • If present, remove the external TCC VFS bar code label.
      • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

      No 

      NOTE:

      This transmission is equipped with a solenoid for the Torque Converter Clutch (TCC) that is a Variable Force Solenoid (VFS) with close tolerance Pressure/Inductance (PI) curve. If replacing the PCM, it is necessary to transfer the PI data from the old PCM to the new PCM using the scan tool. If the PCM being replaced is non-responsive, the PI data can be retrieved from a 2-D bar code on the exterior of the transmission case. This is done with the scan tool using the "Program Torque Converter Solenoid PI Curve" routine.

      Early build transmissions will have the 2-D barcode label on the right side of the transmission case. Late build transmissions will have the label attached to a machined pad at the top of the case, near the rear of the transmission. The data must be entered into the scan tool in order to upload the information to the PCM. In the event that the exterior BAR code is missing, or it is suspected that the valve body or TCC solenoid has been replaced without uploading the correct PI data into an existing PCM, the transmission oil pan must be removed to retrieve the information from the 2-D bar code on the body of the TCC solenoid.

      • 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. Refer to REMOVAL AND INSTALLATION .
      • With the scan tool, perform a Quick Learn.
      • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .