Sleep Mode

BODY CONTROL UNIT

86-3-4

DESCRIPTION AND OPERATION

Load Disconnection
The BCU supplies various electrical loads on the vehicle, such as the glovebox lamp, reading lamps, luggage 
compartment lamps, etc., that can be switched on and remain on when the vehicle is parked. A central load 
disconnection feature in the BCU ensures the battery is not discharged in the event these loads are switched on 
continuously. The trigger time after the ignition is switched off is 16 minutes and is independent of the sleep mode 
timer.

The BCU also disconnects the following loads while the engine cranks, to maximise the available power from the 
battery:

l

Wipers

l

Washer pump

l

Headlamp cleaning

l

Window regulators

l

Sunroof.

If the one-touch function of a window or sunroof is active before the load disconnection, the function is not continued 
when engine cranking stops.

Sleep Mode
To conserve power, the entire BCU goes into a 'sleep' mode 16 minutes after signal activity ceases and the ignition 
is switched off. The typical current consumption of the BCU in sleep mode is 1.25 mA. In the sleep mode the BCU is 
in a limited operational mode from which it can be awakened by certain relevant wake-up signals. After being 
awakened, the BCU remains awake for 1 minute if no action is triggered. If an action is triggered, the BCU remains 
awake for at least 16 minutes.

BCU

Automatic locking 2 minutes after 
unlocking without opening

Active/ Inactive

BCU

Automatic locking after driving off

Active/ Inactive

Car

BCU

Automatic locking threshold speed 
after driving off

2.5 to 17.5 mph (4 to 28 km/h) at 
fixed intervals

Car

BCU

Driver's window one-touch open 
function

Active/Inactive

Car

BCU

Driver's window one-touch close 
function

Active/Inactive

Car

BCU

Front passenger window one-touch 
open function

Active/Inactive

Car

BCU

Front passenger window one-touch 
close function

Active/Inactive

Car

BCU

Rear windows one-touch open 
function

Active/Inactive

Car

BCU

Rear windows one-touch close 
function

Active/Inactive

Car

BCU

Window switch-off criterion

Europe
NAS

Car

BCU

Wiper reset (only without rain 
sensor)

Active/Inactive

Car

BCU

Comfort function via remote control, 
open all windows and sunroof

Active/Inactive

Car

BCU

Comfort function via remote control, 
close all windows and sunroof

Active/Inactive

Car

BCU

Sunroof one-touch slide open 
function

Active/Inactive

Car

BCU

Sunroof one-touch slide close 
function

Active/Inactive

Car

BCU

Automatic locking after driving off

Active/ Inactive

Key

BCU

Remote central locking actuation

1st press open driver's door, 2nd 
press open all doors
1st press open all doors 

Key

 Control Unit

Function

Parameter

Memory Type