Another computer on the network has stopped hearing the transmission computer. The driver may notice harsh shifts, a stuck gear or several warning lights.
Causes vary by car. Test before you order a part.
Likely causes, most common first
- Poor power or ground at the transmission computer
- Damaged CAN wiring or connector
- Weak battery
- Faulty transmission computer
Parts usually involved
- Transmission computer Find at suppliers
- CAN wiring Find at suppliers
- Fuse Find at suppliers
- Battery Find at suppliers
Test before you replace
Check whether the transmission computer answers a scan tool, then test its power, grounds and CAN lines.
General guidance for generic OBD2 codes. Always follow the maker's procedure for the car in front of you.