Body Control Module: Description and Operation

The BPM electronically controls many vehicle functions. It responds when a switch is actuated by providing output signals to the appropriate devices, either directly or indirectly via relays. In addition the BPM establishes an ISO network link with the Security and Locking Control Module (SLCM) and utilizes the SCP network to exchange data between the body system modules.

The following tables are published for guidance purposes and only provide a rough indication of the correlation between circuit inputs and outputs; due to the complexity and necessary functional interaction required for the vehicle there are many circuits where inputs and outputs overlap.

Malfunction of modules must always be analyzed using the PDU as recommended in Diagnosis and Testing.

Inputs/outputs


Exterior lights circuit
BPM inputs from: BPM outputs to:
Front fog switch Front fog relay

Rear fog switch Low beam relay

Low beam switch High beam relay

High beam switch Side marker and license plate relay

Side lights switch Side and tail lights

Headlamp flash switch Direction indicators

Direction indicator switch Hazard status bulb

Hazard switch Indicators via SCP

Front fog

Low beam

High beam

Side light

Direction

Hazard warning

Status LEDS

Front fog

Rear fog

NOTE: The reverse lights and rear fog lights are NOT controlled by the BPM; refer to Security and Locking Control Module.


Interior lights circuit
BPM inputs from: BPM outputs to:
Header console courtesy light switch Instrument and switch Illumination.

Fade 1 (Header console courtesy lamps)

SCP Fade 2 (E-post courtesy lamps)

Map lights

Sun visor lamps

Glovebox lamp

Trunk lamps

Washer/wiper circuit
Wiper park switch Power wash relay

Low screen wash switch Wiper motor run

Wiper slow speed switch Screen wash pump

Wiper fast speed switch Wiper fast/slow speed

Wiper intermittent switch

Wash/wipe switch

Ignition circuit
Ignition position Transit relay

Auxiliary position Mirror fold out

Mirror fold flat

Central door locking circuit
Central locking button Central door locking relay

Valet switch SCP (door modules, security and locking control module)

SCP (door modules) Sun roof ECU

Security system circuit
Hood security switch Horn relay

Horn switches Active security sounder

Central locking button Passive security sounder

SCP (door modules, security and Security status LED
locking control module)

Central door locking relay

ISO link (key transponder module) SCP (door modules, security and locking control module)

ISO link (key transponder module)

Steering column adjustment circuit
Column adjustment switches Column tilt motor

Column reach motor

Gear shift interlock circuit
Neutral switch Keylock solenoid

J-gate not in park Gearshift interlock solenoid

Seat heaters circuit
Seat heater switches Seat heater relay

Status LED

Seat buckle circuit
Seat buckle Audible warning

SCP