Fault Code 950: Neutral Status 1
J1939: SA 3 SPN 3648 FMI 12
Overview
The Endurant HD Series transmissions are equipped with position sensors to monitor shift rail positions and speed sensors to monitor shaft speeds. The sensor information is provided to the Transmission Control Module (TCM) for the purpose of making shift decisions, confirming gear engagement, and monitoring shift rail positions.
The TCM is configured to accept Shift Mode request messages from the vehicle Driver Interface Device over the Primary Data Link (J1939A). A second Shift Mode request signal from the vehicle Driver Interface Device is also provided on a separate circuit.
The TCM compares Shift Mode requests to the shift rail positions and shaft speeds (ratio calculation) to ensure the transmission is operating properly.
Detection
The TCM monitors Shift Mode request messages and gear position. If a system failure is detected, the fault is set Active.
Conditions to Set Fault Code Active
FMI 12 – Bad Intelligent Device: Inappropriate selection of a non-Neutral Shift Mode when Neutral Shift Mode was requested.
Fallback
FMI 12:
- Urge to Move and Creep Mode prohibited
- Non-Neutral modes prohibited
- Clutch engagement prohibited
- PTO Mode prohibited
Conditions to Set Fault Code Inactive
FMI 12: Key cycle and fault condition no longer exists.
Possible Causes
FMI 12:
- TCM
- Software issue
- Internal failure
Additional Tools
- None
Fault Code 950 Troubleshooting
Set vehicle parking brake and chock wheels.
Record transmission fault codes, FMIs, occurrences, and timestamps from Service Activity Report created during the Diagnostic Procedure.
If Fault Code 950 is Inactive and there are other Active vehicle or transmission fault codes, troubleshoot all Active fault codes. Go to Step V
If Fault Code 950 FMI 12 is Active, replace Transmission Control Module (TCM). Go to Step V
If Fault Code 950 FMI 12 is Inactive, Go to Step V
Key off.
Reconnect all connectors and verify 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 vehicle operates properly, test complete.
If Fault Code 950 sets Active, Go to Step A
If a fault code other than 950 sets Active, troubleshoot per the Fault Code Isolation Procedure Index.