Fault Code 315: Rail D Position
J1939: SA 3 SPN 5941 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 D actuates the Rail D sliding clutch to engage the Primary Driven Gear or Reverse 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 D 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 D Position Sensor indicated Rail D moved beyond the calibrated Primary Driven Gear engagement position for 1 second.
FMI 1 – Data Valid But Below Normal – Most Severe: Rail D Position Sensor indicated Rail D moved beyond the calibrated Reverse Gear engagement position for 1 second.
FMI 2 – Data Erratic: Rail D Position Sensor out of normal operating duty cycle (5% to 95%) for 1 second.
FMI 3 – Voltage Above Normal or Shorted High: Rail D Position Sensor shorted to power for 1 second.
FMI 4 – Voltage Below Normal or Shorted Low: Rail D Position Sensor shorted to ground for 1 second.
FMI 5 – Current Below Normal or Open Circuit: Rail D Position Sensor open circuit for 1 second.
FMI 6 – Current Above Normal or Grounded Circuit: Rail D Position Sensor out of normal operating voltage (4.75V to 5.25V) for 1 second.
FMI 7 – Mechanical System Not Responding: Rail D Position Sensor indicated movement from neutral while Rail C was engaged into the Primary Drive Gear or Secondary Driven Gear during an interlock function test.
FMI 8 – Abnormal Frequency: Rail D Position Sensor out of normal operating frequency for 1 second.
FMI 9 – Abnormal Update Rate: Rail D Position Sensor could not detect magnet for 1 second.
FMI 10 – Abnormal Rate Of Change: Rail D Position Sensor reporting rate of change exceeded when no movement commanded for 1 second.
FMI 12 – Bad Intelligent Device: Rail D Position Sensor internal self-check out of range for 1 second.
FMI 14 – Special Instructions: Rail D Position Sensor reporting a partial or full Reverse Gear engagement position while speed sensors and Rail C Position Sensor reports a Primary Drive Gear or Secondary Driven Gear engagement position for 1 second.
FMI 15 - Data Valid but Above Normal (Least Severe): Rail D Position Sensor reporting uncommanded movement toward the Primary Driven Gear from the neutral position while C Position Sensor reports a Primary Drive Gear or Secondary Driven Gear engagement position for 2 seconds.
FMI 16 - Data Valid but Above Normal (Moderately Severe): Rail D Position Sensor reporting uncommanded movement toward neutral from the Primary Driven Gear engagement position while speed sensors report a valid Primary Driven Gear ratio.
FMI 17 – Data Valid but Below Normal (Least Severe): Rail D Position Sensor reporting uncommanded movement toward the Reverse Gear from the neutral position while Rail C Position Sensor reports a Primary Drive Gear or Secondary Driven Gear engagement position for 2 seconds.
FMI 18 – Data Valid but Below Normal (Moderately Severe): Rail D Position Sensor reporting uncommanded movement toward neutral from the Reverse Gear engagement position while speed sensors report a valid Reverse Gear ratio.
FMI 20 – Data Drifted High: Rail D Position Sensor reporting Primary Driven Gear disengagement while speed sensors report a valid Primary Driven Gear ratio for 1 second.
FMI 21 – Data Drifted Low: Rail D Position Sensor reporting Reverse Gear disengagement while speed sensors report a valid Reverse Gear ratio for 1 second.
FMI 31 – Condition Exists: Rail D Position Sensor reporting a partial or full Primary Driven Gear engagement while speed sensors and Rail C Position Sensor reports a Primary Drive Gear or Secondary Driven 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 D position is known and fully engaged
- Amber warning lamp on
- Shift Rail D movement prohibited
- If Rail D position is not known or not fully engaged:
- Amber warning lamp on
- Shift Rail D 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, 10: Rail D Position Sensor in range for 10 seconds.
FMI 0, 1, 7, 11, 14, 15, 16, 18, 20, 21, 31: Key cycle and condition no longer exists.
FMI 12: Rail D Position Sensor internal self-checks in range for 10 seconds.
Possible Causes
FMI 0, 1:
- MTM
- Rail D Yoke
- Internal Transmission
- Rail D Sliding Clutch
FMI 2, 3, 4, 5, 6, 8:
- MTM - Rail D 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 D 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 D
- Valve Pack B
- Valve Pack C
- Rail D cylinder
- Rail D yoke
- Rail D detent
- Internal Transmission
- Rail D sliding clutch
- Main Shaft
FMI 8:
- MTM - Rail D 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 D Cylinder
- Magnet loose
- Magnet detached
- MTM - Rail D Position Sensor
- Loose
- Damaged
FMI 10, 14, 20, 21, 31:
- MTM - Rail D Position Sensor
- Internal failure
FMI 12:
- TCM
- Software issue
- Internal failure
FMI 15, 16, 17, 18:
- MTM - Rail D Position Sensor
- Internal failure
- MTM - Rail D 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) |
Fault Code 315 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 315 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 315 FMI 8 and all the following fault codes are Active:
- Fault Code 200 FMI 14
- Fault Code 275 FMI 5
- Fault Code 295 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 315 FMI 8 is Active or Inactive, Go to Step B
If Fault Code 315 FMI 0, 1, 7 is Active or Inactive, Go to Step F
I If Fault Code 315 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 26 and Pin 27. Record reading in table.
Key on.
Measure voltage at the Eaton Breakout Box between Pin 25 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 the 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 | 25 to 27 | 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 14 and Pin 15. Record reading in table.
Key on.
Measure voltage at the Eaton Breakout Box between Pin 25 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 | 25 to 15 | 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 Primary Driven Gear for excessive fore and aft movement.
Inspect the Reverse 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
Inspect the Rail D Sliding Clutch yoke slot for wear.
Shift the Rail D Sliding Clutch to the neutral position (if necessary).
Shift the Rail D Sliding Clutch into the Primary Driven Gear engagement position and return to neutral.
Shift the Rail D Sliding Clutch into the Reverse Gear engagement position and return to neutral.
If the Rail D Sliding Clutch shifts into all three positions, replace the Mechatronic Transmission Module (MTM). Go to Step V
If the Rail D Sliding Clutch does not shift into all three positions, Go to Step H
Inspect Rail D Yoke for wear.
If no yoke wear is evident, inspect Rail D 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
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 315 sets Active during operation, Go to Step A
If a fault code other than 315 sets Active, troubleshoot per the Fault Code Isolation Procedure Index.