Envoy 2WD V6-4.3L VIN W (1998)
Body Control Module: Description and Operation
Body Control System Circuit Description
Ambient Level Sensor
The ambient light level sensor has the following 2 states:
^
The LIGHT state
^
The DARK state
If the headlamp switch is set to AUTO while in the LIGHT state, the following components will stay fully bright:
^
The radio
^
The PRNDL
^
The 4-wheel drive switch
^
The overhead console
^
The radio
^
The PRNDL
^
The 4-wheel drive switch
^
The overhead console
^
The radio
^
The PRNDL
^
The 4-wheel drive switch
^
The overhead console
The above components will STEP dim with the dimming control when the headlamp switch is set to one of the following positions while in the LIGHT
state:
^
PARK LAMP
^
HEADLAMP
The above components will STEP dim with the dimming control when the headlamp switch is set to one of the following positions while in the DARK
state:
^
AUTO
^
PARK LAMP
^
HEADLAMP
Asleep States
The BCM is asleep when the BCM has stopped controlling or monitoring devices and has become idle again.
The BCM enters the asleep state and goes into the low power mode when the following conditions exist:
^
The ignition switch is in the LOCK position.
^
20 minutes elapse without any wake-up signals. If the BCM is in the low power mode and detects a wake-up, the BCM will enter into the wake-up
state and then enter the high power mode.
The BCM will return to the low power mode when the following actions occur:
^
The ignition switch is in the LOCK position.
^
20 minutes elapse without any wake-up signals.
Audible Warnings
The BCM will sound a chime after the BCM determines that a driver warning sound is needed.
Key in Reminder
A chime will sound when the following conditions exist:
^
The ignition switch is not in the RUN or CRANK position.
^
The ignition key is in the ignition key cylinder.
^
The driver door is opened.
Refer to Audible Warnings for more information.
Headlamp Reminder
A chime will sound when the following conditions exist:
^
The headlamp switch is in the PARK LAMP or HEADLAMP position.
^
The dome lamp switch (thumbwheel) is not at the FULL DOWN (Max Dim) position.
^
The ignition switch is in the OFF position or ACC position.
The headlamp reminder chime will not sound if the following conditions exist:
^
The dome lamp switch is in the FULL DOWN position (Max Dim).
