Fault Code 275: Rail B Position
J1939: SA 3 SPN 4219 FMI 0, 1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 14, 16, 18, 20, 21, 31
Overview
The Endurant HD transmission is equipped with position sensors to monitor shift rails B, C, D and E. The position sensors detect the rail position through the proximity of a magnet mounted to each shift rail. Shift Rail B actuates the Rail B synchronizer to engage the Primary or Secondary Drive 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 the Rail B Position. If a system failure is detected, the TCM sets the fault code Active.
Conditions to Set Fault Code Active
FMI 0 – Data Valid But Above Normal – Most Severe: Rail B Position Sensor indicated Rail B moved beyond the calibrated Secondary Drive Gear engagement position for 1 second.
FMI 1 – Data Valid But Below Normal – Most Severe: Rail B Position Sensor indicated Rail B moved beyond the calibrated Primary Drive Gear engagement position for 1 second.
FMI 2 – Data Erratic: Rail B Position Sensor out of normal operating duty cycle (5% to 95%) for 1 second.
FMI 3 – Voltage Above Normal or Shorted High: Rail B Position Sensor shorted to power for 1 second.
FMI 4 – Voltage Below Normal or Shorted Low: Rail B Position Sensor shorted to ground for 1 second.
FMI 5 – Current Below Normal or Open Circuit: Rail B Position Sensor open circuit for 1 second.
FMI 6 – Current Above Normal or Grounded Circuit: Rail B Position Sensor out of normal operating voltage (4.75V to 5.25V) for 1 second.
FMI 8 – Abnormal Frequency: Rail B Position Sensor out of normal operating frequency for 1 second.
FMI 9 – Abnormal Update Rate: Rail B Position Sensor could not detect magnet for 1 second.
FMI 10 – Abnormal Rate Of Change: Rail B Position Sensor reporting rate of change exceeded when no movement commanded for 1 second.
FMI 11 – Root Cause Unknown: Rail B Position Sensor and speed sensors report a mismatch for 1 second.
FMI 12 – Bad Intelligent Device: Rail B Position Sensor internal self-check out of range for 1 second.
FMI 14 – Special Instructions: Rail B Position Sensor reporting a Secondary Drive Gear engagement position while speed sensors report a gear ratio different to a Secondary Drive Gear ratio for 1 second.
FMI 16 - Data Valid but Above Normal (Moderately Severe): Rail B Position Sensor reporting uncommanded movement toward neutral from Secondary Drive Gear engagement position while speed sensors report a valid Secondary Drive Gear ratio.
FMI 18 – Data Valid but Below Normal (Moderately Severe): Rail B Position Sensor reporting uncommanded movement toward neutral from Primary Drive Gear engagement position while speed sensors report a valid Primary Drive Gear ratio.
FMI 20 – Data Drifted High: Rail B Position Sensor reporting Secondary Drive Gear disengagement while speed sensors report a valid Secondary Drive Gear ratio for 1 second.
FMI 21 – Data Drifted Low: Rail B Position Sensor reporting Primary Drive Gear disengagement while speed sensors report a valid Primary Drive Gear ratio for 1 second.
FMI 31 – Condition Exists: Rail B Position Sensor reporting Primary Drive Gear engagement while speed sensors report a gear ratio different to a Primary Drive Gear ratio for 1 second.
Fallback
FMI 0, 1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 14, 16, 18, 20, 21, 31
- If Rail B position is known and fully engaged:
- Amber warning lamp on
- Shift Rail B movement prohibited
- If Rail B position is not known or not fully engaged:
- Amber warning lamp on
- Shift Rail B movement prohibited
- Non-Neutral Modes prohibited
- PTO mode prohibited
- If vehicle is moving – Red stop lamp on
Conditions to Set Fault Code Inactive
FMI 2, 3, 4, 5, 6, 8, 9: Rail B Position Sensor in range for 10 seconds.
FMI 0, 1, 10, 11, 14, 16, 18, 20, 21, 31: Key cycle and condition no longer exists.
FMI 12: Rail B Position Sensor internal 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
- 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 8:
- MTM - Rail B Position Sensor
- Damaged
- Internal failure
- MTM - Transmission Harness
- Wiring shorted to power, shorted to ground or open.
- TCM
- Incorrect MTM Type configured
- Software issue
- Internal failure
FMI 5:
- MTM - Rail B Position Sensor
- Damaged
- Internal failure
- MTM - Transmission Harness
- Wiring shorted to power, shorted to ground or open.
- TCM
- Incorrect MTM Type configured
- Software issue
- Internal failure
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 16, 18:
- MTM - Rail B Position Sensor
- Internal failure
- MTM - Rail B Detent
- Weak or broken spring
- Worn shift rail or detent
Additional Tools
- Endurant HD Service Manual TRSM0950
- Eaton Breakout Box with 74-Way Eaton Diagnostic Adapter - RR1029TR
- Digital Volt/Ohm Meter (DVOM)
- Rail B Synchronizer Engagement Tool - RR1088TR
Component Identification
 |
1. Transmission Control Module (TCM) Cover 2. Transmission Control Module (TCM) 3. 74-Way Transmission Harness Connector (MTM-side) 4. 74-Way Transmission Harness Connector (TCM-side) 5. Transmission Control Module (TCM) Seal 6. Mechatronic Transmission Module (MTM) |
Fault Code 275 Troubleshooting
Set vehicle parking brake and chock wheels.
Record the transmission fault codes, FMIs, occurrences, and timestamps from the Service Activity report created during the Diagnostic Procedure.
If Fault Code 275 FMI 2, 3, 4, 6, 8, 9, 10, 16, 18, 20, 21 is Active or Inactive, Go to Step B
If Fault Code 275 FMI 5 and all the following fault codes are Active:
- Fault Code 200 FMI 14
- Fault Code 295 FMI 8
- Fault Code 315 FMI 8
- Fault Code 320 FMI 8
Note: Fault Code 596 FMI 5 may also be Active depending on MTM Type configured in TCM.
Go to Configure Mechatronic Transmission Module (MTM) Type. Go to Step V
If Fault Code 275 FMI 5 is Active or Inactive, Go to Step B
If Fault Code 275 FMI 0, 1 is Active or Inactive, Go to Step F
If Fault Code 275 FMI 11, 14, 31 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 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
Key off.
Remove the TCM from the MTM with the 20-Way Vehicle Harness Connector and 20-Way TCM Body Harness Connector connected.
Inspect the TCM side of the 74-Way Transmission Harness Connector, verify the connector is free from contamination and corrosion; the terminals are not bent, spread or loose; and there is no damage to the connector body.
Inspect the TCM Seal, verify the seal is properly installed and not damaged.
If contamination or damage is found to the TCM side of the 74-Way Transmission Harness Connector, replace the Transmission Control Module (TCM) and Mechatronic Transmission Module (MTM). Go to Step V
Note: MTM removal and installation requires the transmission to be removed from the vehicle. Reference Endurant HD Service Manual TRSM0950, Transmission Removal Service Procedure.
If no contamination or damage is found, Go to Step C
Key on with engine off.
Connect ServiceRanger.
Go To “Configuration”.
Select “Advanced”.
Note: If “Advanced” is not indicated, TCM software is unable to determine MTM Type. Go to Step 6.
Record “MTM Type” Current Value, go to Step 7.
Locate MTM part information tag and record MTM Part Number (Item 1) in table.
Compare MTM Part Number recorded in Step 6 with MTM Part Number in table to determine MTM Type.
If MTM Type is PS-393, Go to Step D
If MTM Type is PS-496, Go to Step E
| MTM Part Number on tag | |
|---|---|
| MTM Part Number | MTM Type |
| A-10000715 | PS-393 |
| A-10002594 | |
| A-10004202 | |
| A-10004231 | PS-496 |
| A-10004356 | |
| A-10004383 | |
Key off.
Connect the Eaton Breakout Box with 74-Way Eaton Diagnostic Adapter to the TCM side of the 74-Way Transmission Harness Connector.
Measure resistance at the Eaton Breakout Box between Pin 58 and Pin 59. Record reading in table.
Key on.
Measure voltage at the Eaton Breakout Box between Pin 57 and Pin 59. Record reading in table.
Compare reading(s) in table.
If readings are in range, replace the Mechatronic Transmission Module (MTM). Go to Step V
Note: MTM removal and installation requires the transmission to be removed from the vehicle. Reference Endurant HD Service Manual TRSM0950, Transmission Removal Service Procedure.
If readings are out of range, replace Transmission Control Module (TCM). Go to Step V
| Ignition State | Pins | Range | Reading(s) |
|---|---|---|---|
| Key off | 58 to 59 | 7.5k–22k Ohms | |
| Key on | 57 to 59 | 4.75–5.25 V |
Key off.
Connect the Eaton Breakout Box with 74-Way Eaton Diagnostic Adapter to the TCM side of the 74-Way Transmission Harness Connector.
Measure resistance at the Eaton Breakout Box between Pin 36 and Pin 37. Record reading in table.
Key on.
Measure voltage at the Eaton Breakout Box between Pin 35 and Pin 37. Record reading in table.
Compare reading(s) in table.
If readings are in range, replace the Mechatronic Transmission Module (MTM). Go to Step V
Note: MTM removal and installation requires the transmission to be removed from the vehicle. Reference Endurant HD Service Manual TRSM0950, Transmission Removal Service Procedure.
If readings are out of range, replace Transmission Control Module (TCM). Go to Step V
| Ignition State | Pins | Range | Reading(s) |
|---|---|---|---|
| Key off | 36 to 37 | 7.5k–22k Ohms | |
| Key on | 35 to 37 | 4.75–5.25 V |
Key off.
Remove MTM.
Note: MTM removal and installation requires the transmission to be removed from the vehicle. Reference Endurant HD Service Manual TRSM0950, Transmission Removal Service Procedure.
Inspect the Secondary Drive Gear for excessive fore and aft movement.
Inspect the Primary Drive Gear for excessive fore and aft movement
If excessive gear movement is evident, inspect the Main Shaft assembly and input shaft assembly and repair. Go to Step V
If no excessive gear movement is evident, Go to Step G
Inspect the Rail B Synchronizer Sliding Sleeve yoke slot for wear.
Install the Rail B Synchronizer Engagement Tool (RR1088TR).
Note: Reference Manually Actuate Rail B Procedure of the Appendix.
Shift the Rail B Synchronizer Sliding Sleeve into neutral (if necessary).
Shift the Rail B Synchronizer Sliding Sleeve into the Secondary Drive Gear engagement position (fore) and return to neutral.
Shift the Rail B Synchronizer Sliding Sleeve into the Primary Drive Gear engagement position (aft) and return to neutral.
If the Rail B Synchronizer Sliding Sleeve shifts into all three positions, replace the Mechatronic Transmission Module (MTM). Go to Step V
If the Rail B Synchronizer Sliding Sleeve does not shift into all three positions, Go to Step H
Measure Rail B Yoke wear pads with a micrometer. Record reading in table.
If readings are in range, replace the Rail B Synchronizer Assembly. Go to Step V
If readings are out of range, replace the Rail B Synchronizer Assembly and Mechatronic Transmission Module (MTM). Go to Step V
| Shift Yoke | Range | Reading(s) |
|---|---|---|
| Rail B Yoke Wear Pads | 9.500–9.950 mm (0.374-0.392 in) |
Key on with engine off.
Connect ServiceRanger.
Go To “Configuration”.
Select “Advanced”.
Note: If “Advanced” is not indicated, TCM software is unable to determine MTM Type. Go to Step 6.
Record “MTM Type” Current Value, go to Step 7.
Locate MTM part information tag and record MTM Part Number (Item 1) in table.
Compare MTM Part Number recorded in Step 6 with MTM Part Number in table to determine MTM Type.
If MTM Type is PS-393, Go to Step J
If MTM Type is PS-496, Go to Step K
| MTM Part Number on tag | |
|---|---|
| MTM Part Number | MTM Type |
| A-10000715 | PS-393 |
| A-10002594 | |
| A-10004202 | |
| A-10004231 | PS-496 |
| A-10004356 | |
| A-10004383 | |
Key off.
Connect the Eaton Breakout Box with 74-Way Eaton Diagnostic Adapter to the TCM side of the 74-Way Transmission Harness Connector.
Measure resistance at the Eaton Breakout Box between Pin 58 and Pin 59. Record reading in table.
Key on.
Measure voltage at the Eaton Breakout Box between Pin 57 and Pin 59. Record reading in table.
Compare reading(s) in table.
If readings are in range, Go to Step L
If readings are out of range, replace Transmission Control Module (TCM). Go to Step V
| Ignition State | Pins | Range | Reading(s) |
|---|---|---|---|
| Key off | 58 to 59 | 7.5k–22k Ohms | |
| Key on | 57 to 59 | 4.75–5.25 V |
Key off.
Connect the Eaton Breakout Box with 74-Way Eaton Diagnostic Adapter to the TCM side of the 74-Way Transmission Harness Connector.
Measure resistance at the Eaton Breakout Box between Pin 36 and Pin 37. Record reading in table.
Key on.
Measure voltage at the Eaton Breakout Box between Pin 35 and Pin 37. Record reading in table.
Compare reading(s) in table.
If readings are in range, Go to Step L
If readings are out of range, replace Transmission Control Module (TCM). Go to Step V
| Ignition State | Pins | Range | Reading(s) |
|---|---|---|---|
| Key off | 36 to 37 | 7.5k–22k Ohms | |
| Key on | 35 to 37 | 4.75–5.25 V |
Key on.
Measure voltage at the Eaton Breakout Box between Pin 32 and Pin 42. Record reading in table.
Measure voltage at the Eaton Breakout Box between Pin 54 and Pin 55. Record reading in table.
Compare reading(s) in table.
If readings are in range, replace the Mechatronic Transmission Module (MTM). Go to Step V
Note: MTM removal and installation requires the transmission to be removed from the vehicle. Reference Endurant HD Service Manual TRSM0950, Transmission Removal Service Procedure.
If readings are out of range, replace Transmission Control Module (TCM). Go to Step V
| Ignition State | Pins | Range | Reading(s) |
|---|---|---|---|
| Key on | 32 to 42 | 4.75–5.25 V | |
| Key on | 54 to 55 | 4.75–5.25 V |
Key off.
Reconnect all connectors and verify that 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 the vehicle operates properly, test complete.
If Fault Code 275 sets Active during operation, Go to Step A
If a fault code other than 275 sets Active, troubleshoot per the Fault Code Isolation Procedure Index.