Description Of Causes For System Requested AUTOSTART, VEA Generation 2

GENERAL 

The information in this document applies to VEA engines of generation 2. From structure week 2017- a vehicle may have either a engine of generation 1 or generation 2 installed.

HINT: If the vehicle is manufactured in a time period where engines of both generations where available see the parameter "Engine generation" under Diagnostics/Components/Engine Control Module (ECM)/Parameters to determine the generation of the engine. (The parameter is only available in vehicles with structure week 2017-.) 

The Engine Control Module (ECM) detects and saves information about which causes have blocked the automatic start/stop of engine function and what has caused the system to request autostart in autostop mode. This document describes the causes of requested autostart.

HINT: If Engine Control Module (ECM) and/or Central Electronic Module (CEM) detected faults and stored fault codes for components/functions related to automatic start/stop of engine, it is not certain that the event has been stored as cause. 

Some of the reasons listed below will take the vehicle out of autostopped mode not by restarting the engine but by changing mode from autostopped to completely stopped engine. This requires the driver to manually start the engine again by using the start knob.

CAUSES FOR SYSTEM REQUESTED AUTOSTART 

Climate system 

The climate system can request an autostart if the engine needs to be running to ensure the required environment in the passenger compartment.

Power management 

The Central Electronics Module (CEM) can request an autostart if the capacity of the batteries is considered to be insufficient. For example in case of a low state of charge or low battery temperature.

Engine management system 

The Engine Control Module (ECM) can request an autostart for a number of reasons when it is not considered optimal with a stopped engine. Examples of such reasons is too high or low coolant temperature.

Fault detected by engine management system 

The Engine Control Module (ECM) can request an autostart if it has detected a fault that might impact the automatic start/stop functionality.

Brake vacuum 

The brake system can request an autostart if the brake vacuum is insufficient.

ABS failure 

The brake system can request an autostart if it has detected a fault that might impact the automatic start/stop functionality.

Gear position "R" 

Autostart will be requested if the reverse gear is engaged. This reason will also be stored if the vehicle is allowed to roll backwards.

Gear position sport/manual 

Autostart will be requested if the gear selector is moved to manual shifting mode.

Transmission system 

The Transmission Control Module (TCM) can request an autostart for a number of reasons when it is not considered optimal with a stopped engine. An example of such reason is too low transmission oil temperature.

Driver not belted 

Autostart will be requested if the driver seat belt is released, unless the gear selector is in gear position P.

Driver door open 

Autostart will be requested if the driver door is opened.

Hood open 

Autostart will be requested if the hood is opened.

Drive mode 

Autostart will be requested if the driver activates a drive mode that deactivates the automatic start/stop function.

Start/stop manually inactivated 

Autostart will be requested if the driver manually turns off the automatic start/stop function.

Steering 

Autostart will be requested if the steering wheel is turned quickly or if the steering gear is close to its end positions.

Park assist 

Autostart will be requested if the parallel parking system is activated.

Trailer connected 

Autostart will be requested if a trailer is connected to the vehicle.

Altitude/pressure 

Autostart will be requested if the vehicle is at too high altitude.