Unreliable Data from Trionic. See Fault Tracing for Fault Code in Trionic .
Scheme 624
Fault symptoms
CHECK GEARBOX warning lamp on.
The TCM is possibly in Limp-Home mode (emergency operation program).
Conditions
Incorrect information from the Trionic system
Diagnostic help
Incorrect engine torque information on the P-bus causes the TCM to generate diagnostic trouble code P1971.
Incorrect accelerator position information on the P-bus causes the TCM to generate diagnostic trouble code P1971.
See P-BUS AND I-BUS