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 OTHER DTCS
1. Turn the ignition on.
2. With the scan tool, read TCM 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 P0944-LOSS OF HYDRAULIC PUMP PRIME .
  No
  - Go To 2
CHECK FOR EVENT DATA FOR DTC P0841
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 3
  No
  - Repair the DTC(s) reported in the Event Data. Refer to DIAGNOSTIC CODE INDEX .
CHECK EVENT DATA FOR DTC SETTING WHILE IN REVERSE
Does the Event Data show DTC P0841 set while in Reverse?

Yes
- Go To 10
No
- Go To 4
CHECK EVENT DATA FOR DTC SETTING WHILE L/R PRESSURE SWITCH WAS CLOSED
Does the Event Data show the L/R Pressure Switch reading CLOSED when DTC P0841 set?

Yes
- Go To 5
No
- Go To 13
CHECK L/R PRESSURE SWITCH CIRCUITS
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.
3. Install the Transmission Simulator (special tool #8333B, Simulator, Transmission).
4. Turn the ignition on.
5. Turn the Pressure Switch selector to L/R on the Transmission Simulator.
6. With the scan tool, read the L/R Pressure Switch state while pressing the Pressure Switch Test button on the Transmission Simulator.
  Did the L/R Pressure Switch state change from OPEN to CLOSED while pressing the Pressure Switch Test button on the Transmission Simulator?
  
  Yes
  - Go To 6
  No
  - Go To 10
CHECK WIRING AND CONNECTORS
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 66RFE TRANSMISSION VERIFICATION TEST .
  No
  - Go To 7
CHECK EVENT DATA FOR DTC SETTING WHILE IN FIRST GEAR
In the Event Data recorded earlier, does the Event Data show the Present Gear as first gear when DTC P0841 set ?

Yes
- Go To 8
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 IF THE NO. 1 CHECK BALL IS CUT OR DAMAGED
1. Turn the ignition off.
2. Remove the Transmission Valve Body in accordance with the Service Information.
3. Check the No. 1 Check Ball for any cuts or damage.
  Is the No. 1 Check Ball cut or damaged?
  
  Yes
  - 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.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
  No
  - Go To 9
CHECK FOR A DISLODGED REVERSE CARRIER SNAP RING
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
  - 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.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
CHECK THE (T50) L/R PRESSURE CONTROL CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the Transmission Simulator (special tool #8333B, Simulator, Transmission) if it was connected in a previous step or disconnect the Transmission Solenoid/TRS Assembly harness connector.
3. 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.
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 (T50) L/R Pressure Control circuit between the Transmission Solenoid/TRS Assembly harness connector and the GPEC Diagnostic Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 11
  No
  - Repair the (T50) L/R Pressure Control circuit for an open.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
CHECK THE (T50) L/R PRESSURE CONTROL CIRCUIT FOR A SHORT TO GROUND
1. Check for continuity between ground and the (T50) L/R Pressure Control circuit at the GPEC Diagnostic Adaptor.
  Is there continuity between ground and the (T50) L/R Pressure Control circuit?
  
  Yes
  - Repair the (T50) L/R Pressure Control circuit for a short to ground.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
  No
  - Go To 12
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.
CHECK FOR LOW 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 for low fluid level. Check the Primary Oil Filter seal for a split, crack or improperly installed. Refer to 66RFE AUTOMATIC TRANSMISSION - (SERVICE INFORMATION) - 2500 HD for the proper installation procedure. If the fluid level and Primary Oil Filter are OK, check the Main Regulator Valve in the Oil Pump.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
  No
  - Go To 14
CHECK THE (T50) L/R PRESSURE CONTROL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Turn the ignition off.
2. Disconnect the Transmission Solenoid/TRS Assembly harness connector.
3. Disconnect the PCM C1 harness connector.
4. Check for continuity between the (T50) L/R Pressure Control circuit and all other circuits at the PCM C1 harness connector.
  Is there continuity between the (T50) L/R Pressure Control circuit and any other circuit?
  
  Yes
  - Repair the (T50) L/R Pressure Control circuit for a short to another circuit.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
  No
  - Go To 15
CHECK IF DTC RESETS
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.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 66RFE TRANSMISSION VERIFICATION TEST .
  No
  - Go To 16
CHECK WIRING AND CONNECTORS
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 66RFE TRANSMISSION VERIFICATION TEST ).
  No
  - Test complete.