What Causes the Transmission Fault Warning After BMW Auto Start-Stop?
1 Answers
BMW's transmission fault warning after auto start-stop can be attributed to the following reasons: 1. Transmission control program issue: If no obvious faults are found and no error codes appear during diagnosis, consider reprogramming or upgrading the system. 2. Transmission fluid problem: BMW recommends changing transmission fluid every 60,000-100,000 km. Regardless of whether it's the fluid's issue, replacement is advisable. 3. Power circuit issue in the transmission control module: Poor contact between fuses and fuse sockets in the wiring can easily cause socket burnout, leading to intermittent dashboard warnings of "transmission abnormality." Loose transmission grounding is another possibility. If the battery has sufficient charge but the starter doesn't respond during ignition, and the dashboard shows "transmission abnormality," check if the transmission-to-body grounding is secure. 4. Battery problem: A depleted battery often triggers numerous signal transmission/reception error codes when diagnosed. If the horn doesn't sound when pressed, verify if the voltage is indeed below 12V. 5. Transmission hardware issue: Faulty transmission control unit (TCU). If your vehicle displays "transmission abnormality" during cold starts, experiences gear locking, or shows sluggish acceleration—but returns to normal after restarting—yet these issues recur intermittently with increasing frequency (eventually occurring even during warm operation), the TCU is likely malfunctioning.
