The Rail C Aft Solenoid (RCAS) valve is energized by the Transmission Control Module (TCM) to direct Supply Air to the Shift Rail C Cylinder to move the Rail C Shift Yoke and Rail C Sliding Clutch in the aft or rearward direction. The RCAS valve is located in the MTM and connected to the TCM at the 74-Way Transmission Harness Connector.
The Transmission Control Module (TCM) energizes the Rail C Aft Solenoid (RCAS) valve, allowing vehicle supplied air pressure to the Shift Rail C Cylinder to move the Rail C Shift Yoke and Rail C Sliding Clutch in the aft or rearward direction. The RCAS is located in the MTM and connected to the TCM at the 74-Way Transmission Harness Connector.
The TCM monitors the RCAS circuit and Shift Rail C position. If a system failure is detected, the fault is set Active.
FMI 0 – Data Valid But Above Normal (Most Severe): RCAS Low-Side Current value greater than commanded current for 1 second.
FMI 1 – Data Valid But Below Normal (Most Severe): RCAS Low-Side Current value less than commanded current for 1 second.
FMI 3 – Voltage Above Normal or Shorted High: RCAS circuit shorted to power for 2 seconds after RCAS commanded off.
FMI 4 – Voltage Below Normal or Shorted Low: RCAS circuit shorted to ground for 2 seconds after RCAS commanded off.
FMI 5 – Current Below Normal or Open Circuit: RCAS circuit open for 2 seconds after RCAS commanded off.
FMI 6 – Current Above Normal or Shorted Circuit: RCAS circuit shorted to ground for 2 seconds after RCAS commanded on.
FMI 7 – Mechanical System Not Responding: Rail C Position value and speed sensors confirmed uncommanded movement from Splitter Gear toward neutral position.
FMI 8 – Abnormal Frequency: RCAS signal frequency out of range for 1 second.
FMI 12 – Bad Intelligent Device: TCM has detected an internal processing error.
FMI 14 – Special Instructions: Rail C Position value indicated uncommanded movement from neutral position toward Driven Gear 2nd immediately after a shift into neutral position.
FMI 15 – Data Valid but Above Normal (Least Severe): Rail C Position value indicated uncommanded movement from neutral position toward Driven Gear 2nd for 2 seconds.
FMI 16 – Data Valid but Above Normal (Moderately Severe): RCAS commanded on longer than expected increasing solenoid temperature.
FMI 17 – Data Valid but Below Normal (Least Severe): Rail C Position value and speed sensors confirmed uncommanded movement from Splitter Gear toward neutral position.
FMI 18 – Data Valid but Below Normal (Moderately Severe): RCAS circuit voltage lower than expected for 1 second after RCAS commanded on.
FMI 31 – Condition Exists: During a rail calibration, Rail C Position value indicated uncommanded movement from neutral position toward Driven Gear 2nd immediately after a shift into neutral position.
FMI 0, 1, 5, 6, 8, 12, 16, 18:
FMI 3, 4:
FMI 7:
FMI 14:
FMI 15:
FMI 17:
FMI 31:
If Shift Rail C is in a fully engaged or fully disengaged position:
If Shift Rail C is not in a fully engaged or fully disengaged position:
FMI 0, 1, 6, 7, 8, 12, 14, 15, 16, 17, 18, 31: Key cycle and fault condition no longer exist.
FMI 3: RCAS circuit not shorted to power for 10 seconds.
FMI 4: RCAS circuit not shorted to ground for 10 seconds.
FMI 5: RCAS circuit not open for 10 seconds.
FMI 0, 1, 3, 4, 5, 6, 8, 16, 18:
FMI 7, 17:
FMI 12:
FMI 14, 15:
FMI 31:
1. Transmission Control Module (TCM) Cover 2. Transmission Control Module (TCM) 3. 74-Way Transmission Harness Connector (TCM-side) 4. 74-Way Transmission Harness Connector (MTM-side) 5. Transmission Control Module (TCM) Seal 6. Mechatronic Transmission Module (MTM) |
Set vehicle parking brake and chock wheels.
Record transmission fault codes, FMIs, occurrences, and timestamps from Service Activity Report created during the Diagnostic Procedure.
If Fault Code 617 FMI 0, 1, 3, 4, 5, 6, 8, 16, 18, 31 is Active or Inactive, Go to Step B
If Fault Code 617 FMI 12 is Active or Inactive, Contact Eaton Cummins Automated Transmission Technologies for further diagnostic instructions. For Help Line phone numbers, go to Contact Information. Go to Step V
If Fault Code 617 FMI 7, 14, 15, 17 is Active or Inactive, Go to Step E
Key off.
Remove TCM from MTM with 20-Way TCM Vehicle Harness Connector and 20-Way TCM Body Harness Connector connected.
Inspect TCM side of the 74-Way Transmission Harness Connector, verify connector is free from contamination and corrosion; terminals are not bent, spread or loose; and there is no damage to connector body.
Inspect TCM Seal, verify seal is properly installed and not damaged.
If contamination or damage is found, replace Transmission Control Module (TCM) and Mechatronic Transmission Module (MTM). Go to Step V
Note: MTM removal and installation requires transmission be removed from vehicle. Reference Endurant XD Service Manual TRSM0960, Transmission Removal Service Procedure.
If no contamination or damage is found, Go to Step C
Key off.
Connect Eaton Breakout Box with 74-Way Eaton Diagnostic Adapter to MTM side of 74-Way Transmission Harness Connector.
Measure resistance at Eaton Breakout Box between Pin 28 and Pin 29. Record reading in table.
Measure resistance at Eaton Breakout Box between Pin 28 and Ground (TCM mounting stud). Record reading in table.
Compare reading(s) in table.
If readings are in range, Go to Step D
If readings are out of range, replace Mechatronic Transmission Module (MTM). Go to Step V
Note: MTM removal and installation requires transmission be removed from vehicle. Reference Endurant XD Service Manual TRSM0960, Transmission Removal Service Procedure.
Pins | Range | Reading(s) |
---|---|---|
28 to 29 | 3.4–5.5 Ohms | |
28 to ground (TCM mounting stud) | Open Circuit (OL) |
Key off.
Remove Eaton Breakout Box 74-Way Eaton Diagnostic Adapter.
Reinstall TCM to MTM.
Reconnect all connectors and verify all components are properly installed.
Key on with engine off.
Connect ServiceRanger.
Retrieve and record transmission fault codes, FMIs, occurrences, and timestamps.
If Fault Code 617 FMI 0, 1, 3, 4, 5, 6, 8, 16, 18, 31 is Active, replace Transmission Control Module (TCM). Go to Step V
If Fault Code 617 FMI 0, 1, 3, 4, 5, 6, 8, 16, 18, 31 is Inactive, replace Mechatronic Transmission Module (MTM). Go to Step V
Note: MTM removal and installation requires transmission be removed from vehicle. Reference Endurant XD Service Manual TRSM0960, Transmission Removal Service Procedure.
Key off.
Remove MTM.
Note: MTM removal and installation requires transmission be removed from vehicle. Reference Endurant XD Service Manual TRSM0960, Transmission Removal Service Procedure.
Inspect Splitter Gear for excessive fore and aft movement.
Inspect Driven Gear 2nd for excessive fore and aft movement.
If excessive gear movement is evident, inspect Main Shaft Assembly for cause and repair. Go to Step V
If no excessive gear movement is evident, Go to Step F
Inspect Rail C Sliding Clutch yoke slot for wear.
Shift Rail C Sliding Clutch into neutral position (if necessary).
Shift Rail C Sliding Clutch into Splitter Gear engagement position (fore).
Inspect Rail C Sliding Clutch clutching teeth for wear.
Return Rail C Sliding Clutch to neutral position.
Shift Rail C Sliding Clutch into Driven Gear 2nd engagement position (aft).
Inspect Rail C Sliding Clutch clutching teeth for wear.
Return Rail C Sliding Clutch to neutral position.
If Rail C Sliding Clutch shifts into all three positions and no clutching teeth wear is present, replace Mechatronic Transmission Module (MTM). Go to Step V
If Rail C Sliding Clutch does not shift into all three positions or clutching teeth wear is present, replace Rail C Sliding Clutch, Splitter Gear, Driven Gear 2nd and Mechatronic Transmission Module (MTM). Go to Step V
Key off.
Reconnect all connectors and verify all components are properly installed.
Key on with engine off.
Connect ServiceRanger.
Go To “Fault Codes”.
Select “Clear All Faults”.
Operate vehicle and attempt to reset the fault code or duplicate the previous complaint.
Check for fault codes using ServiceRanger.
If no fault codes set and vehicle operates properly, test complete.
If Fault Code 617 sets Active, Go to Step A
If a fault code other than 617 sets Active, troubleshoot per the Fault Code Isolation Procedure Index.