BMW CF12 — Engine Torque Message Alive Signal
- Severity
- Informational
- Module
- EGS
- OBD-II Code
- U114A
Description
Fault code CF12 is stored by the EGS (Electronic Transmission Control) when the alive counter in the engine torque message from the DME or DDE stops incrementing. The EGS continuously monitors the "torque 1" CAN message from engine management to coordinate shift timing, torque converter lockup, and transmission protection strategies. The alive signal is a rolling counter within the CAN message that proves the data is being actively updated — if the counter stalls, the EGS knows the message is stale or the DME has stopped transmitting.
U114A is defined as "Message Monitoring Engine Control Torque 1 Alive Check." The EGS monitors the alive counter in the torque 1 CAN message broadcast by the DME (gasoline) or DDE (diesel). This monitoring runs when battery voltage is between 9V and 16V, terminal 30 is on, and CAN communications are otherwise OK. When the alive counter stops incrementing, the EGS knows the DME/DDE is either not transmitting or the message is stuck/corrupted. The EGS triggers warning lamp ID 419 and illuminates the MIL on the first drive cycle.
Safety Warnings
Loss of the engine torque message means the EGS cannot properly coordinate shifts with engine output. The MIL (check engine light) will illuminate. The transmission may shift harshly or at incorrect times because it cannot anticipate engine torque changes. Have this fault diagnosed promptly — uncoordinated shifts can damage transmission internals.
CF12 - U114A: Engine Torque Message Alive Signal - Alive signal failure — engine torque message
Symptoms
- MIL (check engine light) illuminated — set on the first drive cycle (ID 419)
- Harsh or poorly timed shifts — the transmission cannot coordinate with engine torque
- Possible transmission failsafe mode
- Reduced shift quality — shifts may feel abrupt or delayed
Common Causes
- DME/DDE fault — the engine control module has an internal error and has stopped broadcasting the torque message
- PT-CAN bus wiring fault between the DME/DDE and EGS
- Intermittent CAN bus error — loose connector, damaged wire, or poor termination
- DME/DDE in a fault state due to another issue (check DME/DDE fault memory)
- Low battery voltage causing CAN bus communication instability
Diagnosis Steps
Read DME/DDE fault memory. The root cause is almost always in the engine management system. If the DME/DDE has internal faults, CAN bus errors, or is in a reduced-function state, it may have stopped broadcasting the torque message. Resolve DME/DDE faults first.
Read all modules for CAN faults. If multiple modules report missing messages from the DME/DDE, the issue is either the DME/DDE itself or a PT-CAN bus problem. If only the EGS reports this fault, check the CAN wiring between the EGS and DME/DDE specifically.
Check battery condition. Measure resting voltage (≥12.4V) and perform a load test. CAN communication errors are a common symptom of low battery voltage.
Inspect PT-CAN bus wiring. Check the CAN-H and CAN-L wires between the DME/DDE and EGS for damage. Measure bus resistance at an accessible point: should read approximately 60Ω with ignition off.
If DME/DDE faults are present: Diagnose and repair the engine management system first. The torque message fault in the EGS will resolve once the DME/DDE is operating normally again.
Resolution
- Diagnose and resolve any DME/DDE faults — this is the most likely root cause.
- Repair PT-CAN bus wiring if damaged.
- If the DME/DDE module is faulty: replace and program using ISTA.
- Clear fault codes in both the EGS and DME/DDE after repair.
- Test-drive and verify that the MIL does not return and shift quality is restored.