Endurant XD
TRTS0960 EN-US
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September 2024 - A

Fault Code 275: Rail B Position

J1939: SA 3 SPN 4219 FMI 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 20, 21, 31

Overview

The Endurant XD Series transmissions are equipped with 5 shift rail position sensors and 5 magnets mounted on shift rails A, B, C, D and E. The shift rail positions sensors monitor the position of the shift rail magnet and provide the information to the Transmission Control Module for the purpose of making shift decisions, confirming gear engagement, and monitoring shift rail positions. Shift Rail B actuates the Rail B Synchronizer to engage the Main Drive Gear Low or Splitter Gear. The position sensors are located in the Mechatronic Transmission Module (MTM) and connected to the Transmission Control Module (TCM) at the 74-Way Transmission Harness Connector.

Detection

The TCM monitors Shift Rail B 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): Shift Rail B movement beyond the calibrated Main Drive Gear Low engagement position for 1 second.

FMI 1 – Data Valid But Below Normal (Most Severe): Shift Rail B movement beyond the calibrated Splitter Gear engagement position for 1 second.

FMI 2 – Data Erratic: Rail B Position duty cycle out of range for 1 second.

FMI 3 – Voltage Above Normal or Shorted High: Rail B Position Sensor circuit shorted to power for 1 second.

FMI 4 – Voltage Below Normal or Shorted Low: Rail B Position Sensor circuit shorted to ground for 1 second.

FMI 5 – Current Below Normal or Open Circuit: Rail B Position Sensor circuit open for 1 second.

FMI 6 – Current Above Normal or Grounded Circuit: Rail B Position Sensor signal out of normal operating voltage (4.75V to 5.25V) for 1 second.

FMI 7 – Mechanical System Not Responding: Shift Rail B failed interlock function test. Uncommanded Shift Rail B movement from neutral position while Main Drive Gear was engaged.

FMI 8 – Abnormal Frequency: Rail B Position Sensor signal frequency out of range for 1 second.

FMI 9 – Abnormal Update Rate: Rail B Position Sensor did not detect Shift Rail B magnet for 1 second.

FMI 10 – Abnormal Rate Of Change: Rail B Position value rate of change exceeded when no Shift Rail B movement commanded for 1 second.

FMI 11 – Root Cause Unknown: Rail B Position value indicated Main Drive Gear Low or Splitter Gear engagement, but speed sensors did not indicate a Main Drive Gear Low or Splitter Gear ratio for 2 seconds.

FMI 12 – Bad Intelligent Device: Rail B Position Sensor circuit self-check failure for 1 second.

FMI 14 – Special Instructions: Rail B Position value indicated Main Drive Gear Low engagement position, but Rail A Position Sensor and speed sensors confirmed Main Drive Gear engagement for 1 second.

FMI 15 - Data Valid but Above Normal (Least Severe): Uncommanded Shift Rail B movement from neutral position toward Main Drive Gear Low while Main Drive Gear was engaged for 2 seconds.

FMI 16 - Data Valid but Above Normal (Moderately Severe): Uncommanded Shift Rail B movement from Main Drive Gear Low toward neutral position while speed sensors continued to indicate a Main Drive Gear Low ratio.

FMI 17 – Data Valid but Below Normal (Least Severe): Uncommanded Shift Rail B movement from neutral position toward Splitter Gear while Main Drive Gear was engaged for 2 seconds.

FMI 18 – Data Valid but Below Normal (Moderately Severe): Uncommanded Shift Rail B movement from Splitter Gear toward neutral position while speed sensors continued to indicate a Splitter Gear ratio.

FMI 20 – Data Drifted High: Rail B Position value indicated Main Drive Gear Low disengagement but speed sensors and torque continued to indicate a Main Drive Gear Low ratio for 2 seconds.

FMI 21 – Data Drifted Low: Rail B Position value indicated Splitter Gear disengagement but speed sensors and torque continued to indicate a Splitter Gear ratio for 2 seconds.

FMI 31 – Condition Exists: Rail B Position value indicated Splitter Gear engagement position, but Rail A Position Sensor and speed sensors confirmed Main Drive Gear engagement for 1 second.

Fallback

FMI 0, 1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 20, 21, 31

  • If Rail B position is known and Rail B is either fully engaged or disengaged:
    • Amber warning lamp on
    • Shift Rail B movement prohibited
  • If Rail B position is not known and Rail B is either not fully engaged or disengaged:
    • Amber warning lamp on
    • Shift Rail B movement prohibited
    • Urge to Move and Creep Mode prohibited
    • Inertia Brake activation prohibited
    • Non-Neutral Modes prohibited
    • PTO Mode prohibited
    • If vehicle is moving – Red stop lamp on

FMI 7

  • Amber warning lamp on
  • No degraded modes

Conditions to Set Fault Code Inactive

FMI 0, 1, 7, 10, 11, 14, 15, 16, 17, 18, 20, 21, 31: Key cycle and fault condition no longer exist.

FMI 2: Rail B Position duty cycle in range for 10 seconds.

FMI 3: Rail B Position Sensor circuit not shorted to power for 10 seconds.

FMI 4: Rail B Position Sensor circuit not shorted to ground for 10 seconds.

FMI 5: Rail B Position Sensor circuit not open for 10 seconds.

FMI 6: Rail B Position Sensor signal voltage between 4.75 and 5.25 volts for 10 seconds.

FMI 8: Rail B Position Sensor signal frequency in range for 10 seconds.

FMI 9: Shift Rail B magnet detected for 10 seconds.

FMI 12: Rail B Position Sensor circuit self-checks in range for 10 seconds.

Possible Causes

FMI 0, 1:

  • MTM
    • Rail B Yoke
  • Internal Transmission
    • Rail B Synchronizer

FMI 2, 3, 4, 5, 6, 8:

  • MTM - Rail B Position Sensor
    • Damaged
    • Internal failure
  • MTM - Transmission Harness
    • Wiring shorted to power, shorted to ground or open.
  • TCM
    • Software issue
    • Internal failure

FMI 7:

  • MTM - Rail B
    • Valve Pack A
    • Valve Pack B
    • Rail B cylinder
    • Rail B yoke
    • Rail B detent
  • Internal Transmission
    • Rail B sliding clutch
    • Main Shaft

FMI 9:

  • MTM - Rail B Cylinder
    • Magnet loose
    • Magnet detached
  • MTM - Rail B Position Sensor
    • Loose
    • Damaged

FMI 10, 14, 20, 21, 31:

  • MTM - Rail B Position Sensor
    • Internal failure

FMI 11:

  • MTM - Rail B Position Sensor
    • Internal failure
  • MTM - Countershaft Speed Sensor
    • Internal failure
  • MTM - Input Shaft Speed Sensor
    • Internal failure
  • TCM
    • Software issue
    • Internal failure

FMI 12:

  • TCM
    • Software issue
    • Internal failure

FMI 15, 16, 17, 18:

  • MTM - Rail B Position Sensor
    • Internal failure
  • MTM - Rail B Detent
    • Weak or broken spring
    • Worn shift rail or detent

Additional Tools

  • Endurant XD Service Manual TRSM0960
  • Eaton Breakout Box with 74-Way Eaton Diagnostic Adapter - RR1029TR
  • Digital Volt/Ohm Meter (DVOM)
  • Rail B Synchronizer Engagement Tool - RR1088TR

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 275 Troubleshooting

A
Purpose: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 275 FMI 2, 3, 4, 5, 6, 8, 9, 10, 14, 15, 16, 17, 18, 20, 21, 31 is Active or Inactive, Go to Step B

  • If Fault Code 275 FMI 0, 1, 7 is Active or Inactive, Go to Step D

  • If Fault Code 275 FMI 11 is Active or Inactive, Go to Step G

  • If Fault Code 275 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

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

  1. Key off.

  2. Remove the TCM from the MTM with the 20-Way 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 there is no damage.

C
Purpose:Verify Rail B Position Sensor internal resistance and power supply at TCM.

  1. Key off.

  2. Connect Eaton Breakout Box with 74-Way Eaton Diagnostic Adapter to TCM 74-Way Connector.

    _Graphics/LineArt/TRTS0950_BreakoutBoxtoTCM.png

  3. Measure resistance at Eaton Breakout Box between Pin 36 and Pin 37. Record reading in table.

    _Graphics/LineArt/TRTS0960_FC275_DVOM36and37ohms.png

  4. Key on.

  5. Measure voltage at Eaton Breakout Box between Pin 35 and Pin 37. Record reading in table.

    _Graphics/LineArt/TRTS0960_FC275_DVOM35and37v.png

  6. Compare reading(s) in table.

Ignition StatePinsRangeReading(s)
Key off36 to 377.5k–22k Ohms
Key on35 to 374.75–5.25 V
D
Purpose:Verify mechanical condition of Main Drive Gear Low and Splitter Gear.

  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 Service Procedure.

  3. Inspect Main Drive Gear Low for excessive fore and aft movement.

    _Graphics/LineArt/TRTS0960_FC275_D.png

  4. Inspect Splitter Gear for excessive fore and aft movement.

  • If excessive gear movement is evident, inspect Main Shaft assembly for cause of excessive movement and repair. Go to Step V

  • If no excessive gear movement is evident, Go to Step E

E
Purpose:Verify mechanical condition of the Rail B Synchronizer.

  1. Inspect Rail B Synchronizer Sliding Sleeve yoke slot for wear.

    _Graphics/LineArt/TRTS0960_FC275_E.png

  2. Install Rail B Synchronizer Engagement Tool (RR1088TR).

    Note: Reference Manually Actuate Rail B Procedure of the Appendix.

  3. Shift Rail B Synchronizer Sliding Sleeve into neutral (if necessary).

  4. Shift Rail B Synchronizer Sliding Sleeve into Main Drive Gear Low engagement position (fore) and return to neutral.

  5. Shift Rail B Synchronizer Sliding Sleeve into Splitter Gear engagement position (aft) and return to neutral.

F
Purpose:Verify mechanical condition of the Rail B Yoke.

  1. Measure Rail B Yoke wear pads with a micrometer. Record reading in table.

    _Graphics/LineArt/TRTS0960_FC275_F.png
Shift YokeRangeReading(s)
Rail B Yoke Wear Pads9.500–9.950 mm (0.374-0.392 in)
G
Purpose:Verify Rail B Position Sensor internal resistance and power supply at TCM.

  1. Key off.

  2. Connect Eaton Breakout Box with 74-Way Eaton Diagnostic Adapter to TCM 74-Way Connector.

    _Graphics/LineArt/TRTS0950_BreakoutBoxtoTCM.png

  3. Measure resistance at Eaton Breakout Box between Pin 36 and Pin 37. Record reading in table.

    _Graphics/LineArt/TRTS0960_FC275_DVOM36and37ohms.png

  4. Key on.

  5. Measure voltage at Eaton Breakout Box between Pin 35 and Pin 37. Record reading in table.

    _Graphics/LineArt/TRTS0960_FC275_DVOM35and37v.png

  6. Compare reading(s) in table.

Ignition StatePinsRangeReading(s)
Key off36 to 377.5k–22k Ohms
Key on35 to 374.75–5.25 V
H
Purpose:Verify Input and Countershaft speed sensor supply voltage at TCM.

  1. Key on.

  2. Measure voltage at Eaton Breakout Box between Pin 32 and Pin 42. Record reading in table.

    graphic1338

  3. Measure voltage at Eaton Breakout Box between Pin 54 and Pin 55. Record reading in table.

    graphic1349

  4. Compare reading(s) in table.

Ignition StatePinsRangeReading(s)
Key on32 to 424.75–5.25 V
Key on54 to 554.75–5.25 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.