Fault Code 185: Driver Demanded Torque
J1939: SA 3 SPN 512 FMI 13, 19
Overview
The Transmission Control Module (TCM) receives Driver Demanded Torque messages from a vehicle Electronic Control Unit (ECU) over the Primary Data Link (J1939A). The messages are based off of the accelerator pedal position and other inputs. This information is used to determine transmission performance.
Detection
The TCM monitors Driver Demanded Torque messages. If messages are not available or are invalid, the fault is set Active.
Conditions to Set Fault Code Active
FMI 13 – Out of Calibration: Driver Demanded Torque message not available for 5 seconds.
FMI 19 – Received Network Data in Error: Driver Demanded Torque messages invalid for 5 seconds.
Fallback
FMI 13, 19:
- Amber warning lamp on
- Coast Mode and Neutral Coast prohibited
- Urge to Move and Creep Mode prohibited
- Inertia Brake activation prohibited
- Upshifts prohibited
- Clutch engagements prohibited
- Non-Neutral modes prohibited
- PTO mode prohibited
- Hill Start Aid prohibited
- If vehicle is moving:
- Red stop lamp on
- Transmission downshifts to lowest available start gear
Note: Vehicle may have additional fallback modes. Refer to OEM.
Conditions to Set Fault Code Inactive
FMI 13, 19: Driver Demanded Torque messages available and valid for 10 seconds.
Possible Causes
FMI 13, 19:
- Vehicle Components
- Driver Demanded Torque message not enabled
- Other vehicle ECU(s) faulted
- Vehicle Harness - Primary Data Link (J1939A)
- Wiring shorted to power, shorted to ground or open
- Terminals bent, spread, corroded, or loose
Note: Refer to OEM for troubleshooting a failed system.
Fault Code 185 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 185 is Inactive and there are other Active vehicle or transmission fault codes, troubleshoot all Active fault codes. Go to Step V
If Fault Code 185 FMI 13 is Active, refer to OEM and enable vehicle Driver Demanded Torque message (SPN 512). Go to Step V
If Fault Code 185 FMI 13 is Inactive, Go to Step V
If Fault Code 185 FMI 19 is Active or Inactive, refer to OEM guidelines for repair of the Driver Demanded Torque message (SPN 512). 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 185 sets Active, Go to Step A
If a fault code other than 185 sets Active, go to Fault Code 185: Driver Demanded Torque.