Vehicles Without Auto Stop/Start System
WARNING: This page is about a different car, the 2019 Jaguar XE. However, it is still accessible from the selected car via links, so may be relevant.
If the Remote Function Actuator (RFA) detects a valid smart key the driver will be able to start the engine. When the ignition switch is operated the Body Control Module/Gateway Module (BCM/GWM) transmits a hardwired crank request. The crank request transmitted to the Powertrain Control Module (PCM).
The energized starter relay supplies battery power to the starter solenoid, which energizes and causes the pinion gear to engage with the ring gear.
When the starter solenoid is energized it also closes high-current contacts, which connects battery power from the Battery Junction Box (BJB) to the motor to turn the engine.
For additional information, Refer to: HANDLES, LOCKS, LATCHES AND ENTRY SYSTEMS - PROJECT 8