Description & Operation

A mechanical control cable prevents ignition key from being removed unless gear selector is in Park. With ignition key removed, gear selector locks in Park. See Fig 1 .
All models are equipped with an electronic shift lock system. Transmission Control Module (TCM) controls shift lock system. See Fig 2 . This system locks gear selector in Park or Neutral position unless brake pedal is pushed down. TCM uses shift lock control relay to release a solenoid mounted on gear selector assembly.

Fig 1: Exploded View Of Shift Selector Housing & Ignition Interlock Cable Components

Courtesy of AUDI OF AMERICA, INC.

Fig 2: Identifying TCM & Ignition Interlock Electrical Components

Courtesy of AUDI OF AMERICA, INC.