Operation CHARM: Car repair manuals for everyone.

Principles of Operation




Starting System

Principles of Operation

The Intelligent Access (IA) starting system is electronically controlled by the Remote Function Actuator (RFA) module which acts as the Passive Anti-Theft System (PATS) control function. In order to start the vehicle, the passive key must be inside the vehicle. The vehicle can be started by pressing the start/stop switch in combination with the brake pedal. The starting system uses a Transmission Range (TR) sensor located in the transmission. The TR (Transmission Range) sensor opens/closes a set of 4 switches that are monitored by the PCM to determine the position of the manual lever (P, R, N, D, L). The TR (Transmission Range) sensor prevents operation of the starter motor unless NEUTRAL or PARK is selected and sends a signal to the PCM to start the vehicle. The RFA (Remote Function Actuator) module recognizes the correct electronically coded passive key and provides initial voltage to the starter relay and signals the PCM to provide a ground for the starter relay. The RFA (Remote Function Actuator) module gains control of the starter engagement. The energized relay provides voltage to the starter solenoid with the ignition in the START position, thereby allowing the starter motor to activate. After the PCM One-Touch Integrated Start (OTIS) feature takes over (this feature assists in starting the engine), the RFA (Remote Function Actuator) no longer provides voltage to the starter relay. The energized relay provides voltage to the starter solenoid with the key in the START position, thereby allowing the starter motor to activate.