Diagnostic Test

WARNING: This page is about a different car, the 2017 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR RELATED DTCS
1. With the scan tool, read TCM DTCs and record on the repair order.
  Are any TCM Power Input, Line Pressure, and or Loss of Prime DTCs set?
  
  Yes
  - Repair TCM Power Input, Line Pressure, and or Loss of Prime DTCs. If DTC P0944 is set, perform that diagnostic procedure first. Refer to P0944-LOSS OF HYDRAULIC PUMP PRIME .
  No
  - Go To 2
CHECK FOR PRESSURE SWITCH DTCS
Are two or more pressure switch rationality DTCs set in addition to P0876?

Yes
- Go To 3
No
- Go To 4
CHECK IF ALL PRESSURE SWITCHES READ CLOSED
1. With the scan tool, read and record the Event Data.
  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 all pressure switches CLOSED?
  
  Yes
  - Perform diagnostic procedure for DTC P0882 as if the DTC is Active. Refer to P0882-TCM POWER INPUT LOW .
  No
  - Go To 4
CHECK FOR OTHER DTCS
1. With the scan tool, read TCM DTCs.
  Is DTC P2704 set?
  
  Yes
  - Replace the Transmission Solenoid/TRS Assembly in accordance with the Service Information.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
  No
  - Go To 5
CHECK THE EVENT DATA
In the Event Data recorded earlier, does the Event Data display information for DTC P0876?

Yes
- Go To 6
No
- Perform the diagnostic procedure for the DTC that is shown in the Event Data. Refer to DIAGNOSTIC CODE INDEX .
CHECK IF EVENT DATA WAS SET IN PARK, NEUTRAL OR REVERSE
In the Event Data recorded earlier, did DTC P0876 set in PARK, NEUTRAL or REVERSE?

Yes
- Go To 10
No
- Go To 7
CHECK FOR UD PRESSURE SWITCH STATUS
In the Event Data recorded earlier, did DTC P0876 set with the UD Pressure Switch CLOSED?

Yes
- Go To 10
No
- Go To 8
CHECK 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 the fluid level and adjust as necessary. If the 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 66RFE AUTOMATIC TRANSMISSION - (SERVICE INFORMATION) - 2500 HD for the above procedures.
- Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
No
- Go To 9
CHECK THE (T29) UD PRESSURE SIGNAL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Turn the ignition off.
2. Disconnect all PCM harness connectors.
  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. Important: The GPEC Diagnostic Adaptor can add up to 1.5 Ohms of resistance to the circuit.
4. Connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
5. Disconnect the Transmission Solenoid/TRS Assembly harness connector.
6. Check for continuity between the (T29) UD Pressure Signal circuit and all other circuits at the GPEC Diagnostic Adaptor.
  Is there continuity between the (T29) UD Pressure Signal circuit and any other circuit?
  
  Yes
  - Repair the (T29) UD Pressure Signal circuit for a short to another circuit.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
  No
  - Replace the Transmission Solenoid/TRS Assembly in accordance with the Service Information.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
CHECK THE PCM AND WIRING
1. Turn the ignition off.
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. Failure to do so can 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 (special tool #8333B, Simulator, Transmission).
4. Turn the ignition on.
5. With the Transmission Simulator, turn the Pressure Switch selector switch to the UD position.
6. With the scan tool, read the UD Pressure Switch state while pressing the Pressure Switch Test button on the Transmission Simulator.
  Did the state of the UD Pressure Switch change while pressing the Pressure Switch Test button?
  
  Yes
  - Go To 15
  No
  - Go To 11
CHECK THE (T29) UD PRESSURE SIGNAL CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the Transmission Simulator (special tool #8333B, Simulator, Transmission).
3. Disconnect the PCM C1 harness.
  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.
4. Important: The GPEC Diagnostic Adaptor can add up to 1.5 Ohms of resistance to the circuit.
5. Connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
6. Measure the resistance of the (T29) UD Pressure Signal circuit from the Transmission Solenoid/TRS Assembly harness connector and the GPEC Diagnostic Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 12
  No
  - Repair the (T29) UD Pressure Signal circuit for an open.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
CHECK THE (T29) UD PRESSURE SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Check for continuity between ground and the (T29) UD Pressure Signal circuit at the GPEC Diagnostic Adaptor.
  Is there continuity between ground and the (T29) UD Pressure Signal circuit?
  
  Yes
  - Repair the (T29) UD Pressure Signal circuit for a short to ground.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
  No
  - Go To 13
CHECK THE (T29) UD PRESSURE SIGNAL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Disconnect all PCM harness connectors.
  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.
2. Important: The GPEC Diagnostic Adaptor can add up to 1.5 Ohms of resistance to the circuit.
3. Connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
  NOTE:
  Make sure the Transmission Solenoid/TRS Assembly harness connector is disconnected.
4. Check for continuity between the (T29) UD Pressure Signal circuit and all other circuits at the GPEC Diagnostic Adaptor.
  Is there continuity between the (T29) UD Pressure Signal circuit and any other circuit?
  
  Yes
  - Repair the (T29) UD Pressure Signal circuit for a short to another circuit.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
  No
  - Go To 14
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all PCM harness connectors.
  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.
2. Important: The GPEC Diagnostic Adaptor can add up to 1.5 Ohms of resistance to the circuit.
3. Connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
4. Disconnect all related in-line harness connections (if equipped).
5. Disconnect the related component harness connectors.
6. 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.
7. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
10. With the scan tool, erase DTCs.
11. 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.
12. With the scan tool, read PCM DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Powertrain Control Module (PCM) in accordance with the Service information. Refer to MODULE, POWERTRAIN CONTROL, (PCM) 5.7L / 6.4L, REMOVAL or MODULE, POWERTRAIN CONTROL, (PCM) 6.7L DIESEL, REMOVAL .
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
  No
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
  - Test complete.
WIGGLE TEST USING THE TRANSMISSION SIMULATOR
1. Perform the steps in the previous test while wiggling the wiring harness and connectors pertaining to the UD Pressure Switch.
  Did the state of the UD Pressure Switch change while pressing the Pressure Switch Test button?
  
  Yes
  - Repair the wiring harness and or connectors as necessary.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
  No
  - Go To 16
CHECK THE TRANSMISSION SOLENOID/TRS ASSEMBLY
1. Disconnect the Transmission Simulator and reconnect the Transmission Solenoid/TRS Assembly harness connector.
2. Disconnect the PCM C1 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. Important: The GPEC Diagnostic Adaptor can add up to 1.5 Ohms of resistance to the circuit.
4. Connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
5. Check for continuity between ground and the (T29) UD Pressure Signal circuit at the GPEC Diagnostic Adaptor.
  Is there continuity between ground and the (T29) UD Pressure Signal circuit?
  
  Yes
  - Replace the Transmission Solenoid/TRS Assembly in accordance with the Service Information.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
  No
  - Go To 17
CHECK IF THE DTC RESETS
1. Reconnect all previously disconnected connectors.
2. With the scan tool, erase TCM DTCs.
3. Test drive the vehicle. Using the Event Data recorded earlier, try to duplicate the conditions in which the DTC set.
  Does DTC P0876 reset?
  
  Yes
  - Go To 18
  No
  - Go To 19
CHECK FOR A CUT NO. 2 CHECK BALL
1. Remove the Valve Body in accordance with the Service Information.
2. Check the No. 2 check ball for cuts or damage.
  Is the No. 2 check ball cut or damaged?
  
  Yes
  - Replace the No. 2 check ball. Check for excessive clutch debris in the oil pan. If excessive debris is present, check the UD Clutch and repair as necessary.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
  No
  - Replace the Transmission Solenoid/TRS Assembly in accordance with the Service Information. Check for excessive clutch debris in the oil pan. If excessive debris is present, check the UD Clutch and repair as necessary.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
CHECK 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 set.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
  No
  - Test complete.