Downshift Switch: Description and Operation

Component Diagram:

Circuit Diagram:

Kickdown Function

Trionic has a pedal position sensor that provides information on the position of the accelerator pedal. When the angle of the pedal exceeds a predetermined value, the Trionic sends the information "KICKDOWN ON" over the bus, value ON/OFF.

The control module uses the signal to control the shifting points so that maximum performance is obtained. The kickdown function is available in all shifting programs.

Diagnostics

A diagnostic trouble code will be generated primarily in Trionic if the function is faulty.

When bus communication with Trionic ceases, diagnostic trouble code P1921 is generated and the transmission goes into limp-home mode.

Inaccurate information on the bus causes diagnostic trouble code P1971 to be generated. Depending on the fault, the TCM may activate the emergency operation program (limp-home mode).