P1921
Symptom: CHECK GEARBOX warning lamp on. TCM in limp-home mode.
P1921 |
Fault symptoms
CHECK GEARBOX warning lamp on.TCM in limp-home mode.
Conditions
The diagnostic trouble code is generated when bus communication ceases between Trionic and the TCM (when the engine speed is over 200 rpm and there has been no communication for at least 6 seconds).Diagnostic help
The TCM goes into limp-home mode.If Trionic is not connected to the bus, it will not be possible to start the car.
See P1921 Electrical system.