Intelligent Stop/Start System

WARNING: This page is about a different car, the 2015 Jaguar XF, 2014 Jaguar XF, and 2013 Jaguar XF. However, it is still accessible from the selected car via links, so may be relevant.

The Intelligent Stop/Start system is controlled by the ECM using CAN (Controller Area Network) messages and signals from other system components and modules to determine the correct conditions for system operation.

The Intelligent Stop/Start system detects when it is appropriate to stop and start the engine.

Before the engine is stopped, the following parameters must be detected:

The vehicle must be stopped from a speed greater than 4 km/h (2.5 mph)
Sufficient brake pressure must be applied to the brake pedal to ensure the vehicle is stationary
- OR
The vehicle must be stationary and 'P' (Park) or 'N' (Neutral) selected on the TCS (Transmission Control Switch).
Before the engine is restarted, the following parameters must be detected:
'D' (Drive) or 'S' (Sport) selected on the TCS and the brake pedal is released
The accelerator pedal is pressed, ECM detects a signal from the APP (Accelerator Pedal Position) sensor
A steering wheel paddle switch is operated to select a gear
'R' (Reverse) is selected on the TCS
Climate control system demand increases (signal from the ATCM (Automatic Temperature Control Module)
The vehicle speed exceeds approximately 1 km/h (0.5 mph)
Primary battery and/or secondary battery charge becomes low (signal from the DBM)
Brake vacuum has been reduced from repeated use of pedal with engine not running (detected by the ECM from the brake vacuum sensor)
ECO Stop/start is de-activated using ECO switch in the ICP (Integrated Control Panel).
The following conditions will prevent an ECO stop:
A steering wheel paddle switch has been used to select a gear
The external ambient temperature is less than 0°C (32°F) (detected by the ECM from the AAT (Ambient Air Temperature) sensor)
The external ambient temperature is more than 40°C (104°F) (detected by the ECM from the AAT sensor)
The engine has not reached its optimum operating temperature (detected by the ECM from ECT (Engine Coolant Temperature) sensor)
The driver door is opened (detected by the CJB (Central junction Box) from the door ajar switch)
The driver seatbelt is not fastened (detected by the RCM (Restraints Control Module) from the driver Buckle switch)
The climate control system requires the engine to be running, for example; windshield demist selected
The primary and/or secondary battery charge is low (signal from the DBM)
The hood is open (detected by the CJB from the hood ajar switch)
ECO stop/start is de-activated using the ECO switch in the ICP.

The primary battery is used for the engine Stop/Start. The secondary battery is switched by the DBM to maintain the car systems, for example, audio, climate or lights, which are then unaffected by the engine restart.

Refer to: Battery and Cables (Description and Operation).