Fault code
BMW fault CF16 - Engine torque signal (engine management)
P2637 · Signal invalid
CF16 is set by the GS transmission control module when the engine torque feedback signal received from the DME/DDE over CAN is invalid or missing. The transmission relies on real-time torque data to coordinate clutch engagement and gear changes.
The GS module detected that the torque management feedback signal from the engine control unit is absent, corrupted, or out of range. Monitoring requires 9-16V battery voltage with terminal 30 on and GS communications active.
- Module
- GS
- Severity
- Warning
- Likely cause
- DME/DDE fault
- Common fix
- Resolving the DME/DDE fault
Symptoms
- Check engine light on after the second drive cycle.
- CC-ID 419 (transmission warning) displayed.
- Harsh or delayed gear shifts as the transmission defaults to conservative torque estimates.
- Reduced responsiveness to throttle input during shifts.
Common causes
- DME/DDE not broadcasting valid torque data due to its own internal fault. Check the DME/DDE for stored faults first.
- CAN bus wiring issue between the DME/DDE and GS corrupting the torque message.
- Outdated or corrupted DME/DDE software producing incorrect signal formatting.
- GS module CAN transceiver fault (rare).
Diagnosis
- Read fault memory in both the GS and DME/DDE with ISTA. If the DME/DDE has active faults, those are the root cause.
- Clear the GS fault and test drive. If the fault does not return, it was a transient glitch.
- If the fault returns, check GS live data for the engine torque parameter. It should respond smoothly to throttle changes. A frozen or erratic reading confirms the signal is not arriving correctly.
- Check DME/DDE live data for its transmitted torque value. If the DME broadcasts valid data but the GS does not receive it, the issue is in the wiring between the two modules.
- Inspect wiring between the DME/DDE and GS connectors for damaged pins, corrosion, and chafed insulation near exhaust and bellhousing.
Resolution
In most cases, resolving the DME/DDE fault that prevents valid torque data from being broadcast fixes this code. If CAN wiring is damaged, repair the harness. Clear faults in both modules and test drive to confirm.
Related fault codes
Last updated Jun 17, 2026 · Suggest an edit