Diagnostic Test

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 

• Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .

1. Turn the ignition on.
2. With the scan tool, read all DTCs and record on the repair order.

   Are any Transmission Loss of Prime, TCM Power Input, and or TCM Power Control Circuit DTCs set?

   Yes 

   • Repair Transmission Loss of Prime, TCM Power Input, and or TCM Power Control Circuit DTCs. If DTC P0944 is set, perform that diagnostic procedure first. Refer to DIAGNOSTIC CODE INDEX .

   No 

   • Go To  3

1. With the scan tool, check the Event Data for P0841.
   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 DTC P0841?

   Yes 

   • Go To  4

   No 

   • Repair the DTC(s) reported in the Event Data. Refer to DIAGNOSTIC CODE INDEX .

Does the Event Data show DTC P0841 set while in Reverse?

Yes 

• Go To  11

No 

• Go To  5

Does the Event Data show the L/R Pressure Switch reading CLOSED when DTC P0841 set?

Yes 

• Go To  6

No 

• Go To  14

1. Turn the ignition off.
2. Disconnect the PCM C2 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 GPEC Diagnostic Adaptor to perform the diagnosis.

3. Connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
4. Turn the ignition on.
5. With the scan tool, read the L/R Pressure Switch state while grounding the (T50) L/R Pressure Signal at the GPEC Diagnostic Adapter with a fused jumper wire.

   Did the L/R Pressure Switch state change from OPEN to CLOSED while grounding the (T50) L/R Pressure Signal?

   Yes 

   • Go To  7

   No 

   • Go To  11

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.

   Were any problems found?

   Yes 

   • Repair as necessary.
   • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

   No 

   • Go To  8

In the Event Data recorded earlier, does the Event Data show the Present Gear as first gear when DTC P0841 set?

Yes 

• Go To  9

No 

• Replace the Transmission Solenoid/TRS Assembly in accordance with the Service Information. Refer to ASSEMBLY, TRANSMISSION SOLENOID AND TRS, REMOVAL AND INSTALLATION .
• Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

1. Turn the ignition off.
2. Remove the Transmission Valve Body in accordance with the Service Information. Refer to VALVE BODY, REMOVAL AND INSTALLATION .
3. Check the No. 1 Check Ball for any cuts or damage.

   Is the No. 1 Check Ball cut or damaged?

   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 No. 1 Check Ball and check for clutch debris in the Transmission oil pan. If there is excessive debris, perform internal repairs to the L/R Clutch assembly in accordance with the Service Information.
   • If the Valve Body or the TCC VFS solenoid is replaced, remove the external TCC VFS bar code label from the transmission case.
   • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

   No 

   • Go To  10

1. Looking through the windows in the bottom of the case, check if the snap ring at the front of the Reverse (center) Carrier has dislodged.
   NOTE:

   It may be necessary to pry the Input Annulus Gear Shell rearward to check this snap ring.

   Is the Reverse Carrier Snap Ring dislodged?

   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.

   • Repair as necessary.
   • If the Valve Body or the TCC VFS solenoid is replaced, remove the external TCC VFS bar code label from the transmission case.
   • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

   No 

   • Replace the Transmission Solenoid/TRS Assembly in accordance with the Service Information. Refer to ASSEMBLY, TRANSMISSION SOLENOID AND TRS, REMOVAL AND INSTALLATION .
   • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

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  12

No 

• Repair the circuit for an open or high resistance.
• Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

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.

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  13

1. Disconnect all PCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
   • Proper connector installation.
   • Damaged connector locks.
   • Corrosion.
   • Other signs of water intrusion.
   • Weather seal damage (if equipped).
   • Bent terminals.
   • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
   • Terminals that have been pushed back into the connector cavity.
   • Perform a terminal drag test on each connector terminal to verify proper terminal tension.

   Repair any conditions that are found.

5. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Using the recorded Event and Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read PCM DTCs.

    Did the DTC return?

    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. 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.

    • Replace the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to REMOVAL AND INSTALLATION .
    • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

    No 

    • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .
    • Test complete.

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 

   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.

   • Repair as necessary to correct low line pressure. Check for low fluid level. Check the Primary Oil Filter seal for a split, crack or improperly installed. Refer to the Service Information for the proper installation procedure. If the fluid level and Primary Oil Filter are OK, check the Main Regulator Valve in the Oil Pump.
   • If the Valve Body or the TCC VFS solenoid is replaced, remove the external TCC VFS bar code label from the transmission case.
   • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

   No 

   • Go To  15

1. The ignition must be off when performing a resistance check to find a short between circuits.
2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and every component harness connector containing the circuit being tested. At this time leave all in-line connectors connected. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
3. Connect one lead of the DVOM to the circuit being tested at the GPEC Diagnostic Adapter.
4. With the other lead of the DVOM probe all other circuits at the GPEC Diagnostic Adapter.

Is there continuity between the circuit being tested and any other circuit?

Yes 

• Repair the short between the circuits that have continuity. Use the wiring diagram as a guide to trace the circuits 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  16

1. With the scan tool, erase DTCs.
2. Using the Event and Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
3. With the scan tool, read TCM DTCs.

   Did the DTC return?

   Yes 

   • Replace the Transmission Solenoid/TRS Assembly in accordance with the Service Information. Refer to ASSEMBLY, TRANSMISSION SOLENOID AND TRS, REMOVAL AND INSTALLATION .
   • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

   No 

   • Go To  17

1. The conditions necessary to set the 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. Check for any Service Bulletins that may apply.

   Were any problems found?

   Yes 

   • Repair as necessary.
   • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

   No 

   • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .
   • Test complete.