Endurant XD
TRTS0960 EN-US
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December 2024 - D

Fault Code 647: Rail E Aft Solenoid (A4)

J1939: SA 3 SPN 769 FMI 0, 1, 3, 4, 5, 6, 7, 8, 12, 16, 17, 18

Overview

The Endurant XD Series transmissions are equipped with solenoid valves that direct vehicle Supply Air to and from the shift rail cylinders in the Mechatronic Transmission Module (MTM). Movement of each shift rail is controlled 2 solenoids; a Fore and a Aft.

The Rail E Aft Solenoid (REAS) valve is energized by the Transmission Control Module (TCM) to direct Supply Air to the Shift Rail E Cylinder to move the Rail E Shift Yoke and Rail E Synchronizer in the aft or reward direction. The REAS valve is located in the MTM and connected to the TCM at the 74-Way Transmission Harness Connector.

Detection

The TCM monitors the REAS circuit and Shift Rail E position. If a system failure is detected, the fault is set Active.

Conditions to Set Fault Code Active

FMI 0 – Data Valid But Above Normal (Most Severe): REAS Low-Side Current value greater than commanded current for 1 second.

FMI 1 – Data Valid But Below Normal (Most Severe): REAS Low-Side Current value less than commanded current for 1 second.

FMI 3 – Voltage Above Normal or Shorted High: REAS circuit shorted to power for 2 seconds after REAS commanded off.

FMI 4 – Voltage Below Normal or Shorted Low: REAS circuit shorted to ground for 2 seconds after REAS commanded off.

FMI 5 – Current Below Normal or Open Circuit: REAS circuit open for 2 seconds after REAS commanded off.

FMI 6 – Current Above Normal or Shorted Circuit: REAS circuit shorted to ground for 2 seconds after REAS commanded on.

FMI 7 – Mechanical System Not Responding: Rail E Position value and speed sensors confirmed uncommanded movement from High Range toward neutral position.

FMI 8 – Abnormal Frequency: REAS signal frequency out of range for 1 second.

FMI 12 – Bad Intelligent Device: TCM detected an internal processing error.

FMI 16 – Data Valid but Above Normal (Moderately Severe): REAS commanded on longer than expected increasing solenoid temperature.

FMI 17 – Data Valid but Below Normal (Least Severe): Rail E Position value and speed sensors confirmed uncommanded movement from High Range toward neutral position.

FMI 18 – Data Valid but Below Normal (Moderately Severe): REAS circuit voltage lower than expected for 1 second after REAS commanded on.

Fallback

FMI 0, 1, 3, 4, 5, 6, 8, 12, 18:

  • Amber warning lamp on
  • If Range is in a fully engaged position
    • Shift Rail E movement prohibited
  • If Range Shift is not in a fully engaged position
    • Shift Rail E movement toward Low Range prohibited
    • Urge to move prohibited
    • Non-Neutral modes prohibited
    • PTO Mode Prohibited
  • If vehicle is moving and no start gear available:
    • Red stop lamp on

FMI 7:

  • No degraded modes

FMI 16:

  • Amber warning lamp on
  • Shift Rail E movement toward Low Range prohibited

FMI 17:

  • Amber warning lamp on
  • High Range engagement prohibited

Conditions to Set Fault Code Inactive

FMI 0, 1, 6, 7, 8, 12, 16, 17, 18: Key cycle and fault condition no longer exist.

FMI 3: REAS circuit not shorted to power for 10 seconds.

FMI 4: REAS circuit not shorted to ground for 10 seconds.

FMI 5: REAS circuit not open for 10 seconds.

Possible Causes

FMI 0, 1, 3, 4, 5, 6, 8, 16, 18:

  • MTM - REAS
    • Internal failure
    • Damaged
  • MTM - Transmission Harness
    • Wiring shorted to power, shorted to ground or open
  • TCM
    • Internal failure

FMI 7, 17:

  • MTM - REAS
    • Partially stuck open
  • Internal transmission
    • Rail E Detent
    • Rail E Synchronizer

FMI 12:

  • TCM
    • Software issue
    • Internal failure

Additional Tools

  • Endurant XD Service Manual TRSM0960
  • Eaton Breakout Box with 74-Way Eaton Diagnostic Adapter - RR1029TR
  • Digital Volt/Ohm Meter (DVOM)
  • MTM Alignment Tool (RR1086TR-1)

Component Identification

_Graphics/LineArt/TRTS0960_FC275_ComponentID.png

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)

Fault Code 647 Troubleshooting

A
Purpose:Vent LCA and Check for active or inactive fault codes.

  1. Set vehicle parking brake and chock wheels.

  2. Record transmission fault codes, FMIs, occurrences, and timestamps from Service Activity Report created during the Diagnostic Procedure.

  • If Fault Code 647 FMI 0, 1, 3, 4, 5, 6, 8, 16, 18 is Active or Inactive, Go to Step B

  • If Fault Code 647 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 647 FMI 7, 17 is Active or Inactive, Go to Step E

B
Purpose:Verify condition of TCM 74-Way Connector.

  1. Key off.

  2. Remove TCM from MTM with 20-Way TCM Vehicle Harness Connector and 20-Way TCM Body Harness Connector connected.

    _Graphics/LineArt/TRTS0950_FC511_Check74WayTCM.png

  3. 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.

  4. Inspect TCM Seal, verify seal is properly installed and not damaged.

C
Purpose:Verify Rail E Aft Solenoid resistance and not shorted to ground.

  1. Key off.

  2. Connect Eaton Breakout Box with 74-Way Eaton Diagnostic Adapter to MTM side of 74-Way Transmission Harness Connector.

    _Graphics/LineArt/TRTS0950_FC511_74WaytoMTM.png

  3. Measure resistance at Eaton Breakout Box between Pin 30 and Pin 31. Record reading in table.

    _Graphics/LineArt/TRTS0960_FC647_DVOM30and31ohms.png

  4. Measure resistance at Eaton Breakout Box between Pin 31 and Ground (TCM mounting stud). Record reading in table.

    _Graphics/LineArt/TRTS0960_FC647_DVOM31andGroundohms.png

  5. Compare reading(s) in table.

PinsRangeReading(s)
30 to 313.4–5.5 Ohms
31 to ground (TCM mounting stud)Open Circuit (OL)
D
Purpose:Check for Active or Inactive fault codes.

  1. Key off.

  2. Remove Eaton Breakout Box 74-Way Eaton Diagnostic Adapter.

  3. Reinstall TCM to MTM.

  4. Reconnect all connectors and verify all components are properly installed.

  5. Key on with engine off.

  6. Connect ServiceRanger.

  7. Retrieve and record transmission fault codes, FMIs, occurrences, and timestamps.

E
Purpose: Verify mechanical movement of Rail E Range Synchronizer.

  1. Key off.

  2. Remove MTM.

    Note: MTM removal and installation requires transmission be removed from vehicle. Reference Endurant XD Service Manual TRSM0960, Transmission Removal and MTM Removal Service Procedures.

  3. Install MTM Alignment Tool (RR1086TR-1) onto main housing.

    Note: Reference Appendix/Manually Actuate Rail E Procedure.

  4. Using Rail E Lever, shift Rail E into neutral position (if necessary).

  5. Shift Rail E into High Range engagement position (fore) and return to neutral position.

  6. Shift Rail E into Low Range engagement position (Low) and return to neutral position.

F
Purpose:Verify mechanical movement of Rail E Range Synchronizer without detent.

  1. Remove the Rail E Detent Plug, Spring and Detent.

  2. Install MTM Alignment Tool (RR1086TR-1) onto main housing.

  3. Using Rail E Lever, shift Rail E into neutral position (if necessary).

  4. Shift Rail E into High Range engagement position (fore) and return to neutral position.

  5. Shift Rail E into Low Range engagement position (aft) and return to neutral position.

  • If Rail E Detent could not be removed, Go to Step G

  • If Rail E shifts between neutral, High and Low Range, contact Eaton Cummins Automated Transmission Technologies at +1 800-826-4357 for further diagnostic instructions. Go to Step V

  • If Rail E does not shift between neutral, High and Low Range, Go to Step G

G
Purpose:Verify mechanical condition of Rail E Synchronizer and Shift Rail E.

  1. Remove Rear Housing.

  2. Inspect Rail E Synchronizer, Shift Rail, Detent and Rear Housing Detent bore.

  • Contact Eaton Cummins Automated Transmission Technologies at +1 800-826-4357 for further diagnostic instructions. Go to Step V

V
Purpose:Verify repair.

  1. Key off.

  2. Reconnect all connectors and verify all components are properly installed.

  3. Key on with engine off.

  4. Connect ServiceRanger.

  5. Go To “Fault Codes”.

  6. Select “Clear All Faults”.

  7. Operate vehicle and attempt to reset the fault code or duplicate the previous complaint.

  8. Check for fault codes using ServiceRanger.