Fault Code 295: Rail C Position (TRTS0950)

Endurant HD

TRTS0950 EN-US

November 2024 - B

Fault Code 295: Rail C Position

J1939: SA 3 SPN 4220 FMI 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 17, 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. Rail C actuates the Rail C sliding clutch to engage the Primary Drive Gear or Secondary Driven 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 C 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 C Position Sensor indicated Rail C moved beyond the calibrated Primary Drive Gear engagement position for 1 second.

FMI 1 – Data Valid But Below Normal – Most Severe: Rail C Position Sensor indicated Rail C moved beyond the calibrated Secondary Driven Gear engagement position for 1 second.

FMI 2 – Data Erratic: Rail C Position Sensor out of normal operating duty cycle (5% to 95%) for 1 second.

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

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

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

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

FMI 7 – Mechanical System Not Responding: Rail C Position Sensor indicated movement from neutral while Rail D was engaged into the Primary Driven Gear or Reverse Gear during an interlock function test.

FMI 8 – Abnormal Frequency: Rail C Position Sensor out of normal operating frequency for 1 second.

FMI 9 – Abnormal Update Rate: Rail C Position Sensor could not detect magnet for 1 second.

FMI 10 – Abnormal Rate Of Change: Rail C Position Sensor reporting rate of change exceeded when no movement commanded for 1 second.

FMI 12 – Bad Intelligent Device: Rail C Position Sensor internal self-check out of range for 1 second.

FMI 14 – Special Instructions: Rail C Position Sensor reporting a partial or full Secondary Driven Gear engagement position while speed sensors and Rail D Position Sensor reports a Primary Driven Gear or Reverse Gear engagement position for 1 second.

FMI 15 - Data Valid but Above Normal (Least Severe): Rail C Position Sensor reporting uncommanded movement toward the Primary Drive Gear from the neutral position while D Position Sensor reports a Primary Driven Gear or Reverse gear engagement position for 2 second.

FMI 16 - Data Valid but Above Normal (Moderately Severe): Rail C Position Sensor reporting uncommanded movement toward neutral from the Primary Drive Gear engagement position while speed sensors report a valid Primary Drive Gear ratio.

FMI 17 – Data Valid but Below Normal (Least Severe): Rail C Position Sensor reporting uncommanded movement toward the Secondary Driven Gear from the neutral position while Rail D Position Sensor reports a Primary Driven Gear or Reverse gear engagement position for 2 second.

FMI 18 – Data Valid but Below Normal (Moderately Severe): Rail C Position Sensor reporting uncommanded movement toward neutral from the Secondary Driven Gear engagement position while speed sensors report a valid Secondary Driven Gear ratio.

FMI 20 – Data Drifted High: Rail C Position Sensor reporting Primary Drive Gear disengagement while speed sensors report a valid Primary Drive Gear ratio for 1 second.

FMI 21 – Data Drifted Low: Rail C Position Sensor reporting Secondary Driven Gear disengagement while speed sensors report a valid Secondary Driven Gear ratio for 1 second.

FMI 31 – Condition Exists: Rail C Position Sensor reporting a partial or full Primary Drive Gear engagement while speed sensors and Rail D Position Sensor reports a Primary Driven Gear or Reverse Gear engagement position for 1 second.

Fallback

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

If Rail C position is known and fully engaged
- Amber warning lamp on
- Shift Rail C movement prohibited
If Rail C position is not known or not fully engaged:
- Amber warning lamp on
- Shift Rail C movement prohibited
- Non-neutral modes prohibited
- PTO Mode Prohibited
- If vehicle is moving - Red stop lamp on

FMI 7

Amber warning lamp on
No degraded performance

Conditions to Set Fault Code Inactive

FMI 2, 3, 4, 5, 6, 8, 9: Rail C Position Sensor in range for 10 seconds.

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

FMI 12: Rail C Position Sensor internal self-checks in range for 10 seconds.

Possible Causes

FMI 0, 1:

MTM
- Rail C Yoke
Internal Transmission
- Rail C Sliding Clutch

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

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

FMI 2, 3, 4, 5, 6:

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

FMI 8:

MTM - Rail C 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 C Cylinder
- Magnet loose
- Magnet detached
MTM - Rail C Position Sensor
- Loose
- Damaged

FMI 12:

TCM
- Software issue
- Internal failure

FMI 10, 14, 20, 21, 31:

MTM- Rail C Position Sensor
- Internal failure

FMI 15, 16, 17, 18:

MTM - Rail C Position Sensor
- Internal failure
MTM - Rail C 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)

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)

_Graphics/LineArt/TRTS0950_FC275_ComponentID.png

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 295 Troubleshooting

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

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 295 FMI 2, 3, 4, 5, 6, 9, 10, 14, 16, 18, 20, 21, 31 is Active or Inactive, Go to Step B

If Fault Code 295 FMI 8 and all the following fault codes are Active:

Fault Code 200 FMI 14
Fault Code 275 FMI 5
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 295 FMI 8 is Active or Inactive, Go to Step B

If Fault Code 295 FMI 0, 1, 7, 15, 17 is Active or Inactive, Go to Step F

If Fault Code 295 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

Purpose: Verify condition of 74-Way Transmission Harness Connector.

Key off.
Remove the TCM from the MTM with the 20-Way TCM Vehicle Harness Connector and 20-Way TCM Body Harness Connector20-Way TCM 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 any 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

Purpose:Identify MTM Type

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

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

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 14 and Pin 15. Record reading in table.
Key on.
Measure voltage at the Eaton Breakout Box between Pin 13 and Pin 15. 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	14 to 15	7.5k–22k Ohms
Key on	13 to 15	4.75–5.25 V

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

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 26 and Pin 27. Record reading in table.
Key on.
Measure voltage at the Eaton Breakout Box between Pin 13 and Pin 27. 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	26 to 27	7.5k–22k Ohms
Key on	13 to 27	4.75–5.25 V

Purpose:Verify mechanical condition of the Primary Drive and Secondary Driven Gears.

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 Primary Drive Gear for excessive fore and aft movement.
Inspect the Secondary Driven Gear for excessive fore and aft movement.

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

If no excessive gear movement is evident, Go to Step G

Purpose: Verify mechanical condition of the Rail C Sliding Clutch.

Inspect the Rail C Sliding Clutch yoke slot for wear.
Shift the Rail C Sliding Clutch to the neutral position (if necessary).
Shift the Rail C Sliding Clutch into the Primary Drive Gear engagement position and return to neutral.
Shift the Rail C Sliding Clutch into the Secondary Driven Gear engagement position and return to neutral.

If the Rail C Sliding Clutch shifts into all three positions, replace Mechatronic Transmission Module (MTM). Go to Step V

If the Rail C Sliding Clutch does not shift into all three positions, Go to Step H

Purpose: Verify mechanical condition of the Rail C Yoke.

Inspect Rail C Yoke for wear.

If no yoke wear is evident, inspect Rail C Sliding Clutch and Main Shaft for cause of restricted movement and repair. Go to Step V

If yoke wear is evident, inspect Rail C Sliding Clutch and Main Shaft for cause of restricted movement and repair. Replace Mechatronic Transmission Module (MTM). Go to Step V

Purpose: Verify repair.

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 295 sets Active during operation, Go to Step A

If a fault code other than 295 sets Active, troubleshoot per Fault Code Isolation Procedure Index.