Alero L4-144 2.4L DOHC VIN T SFI (2000)
Body Control Module: Description and Operation
General Information
The Body Control Module (BCM) controls the following systems:
^
A/C compressor
^
Exterior and interior lighting control for the following lamps:
-
Daytime Running Lights (DRL)
-
Automatic lighting control (ALC)
-
Fog lamps
-
Interior lighting
^
Battery rundown protection
^
Audible warnings
^
Instrument cluster indicators
^
Theft deterrent
^
Keyless entry
^
Panic horn
A/C Compressor Control
The Powertrain Control Module (PCM) and the BCM share the hardware and the software for control of the A/C compressor clutch. The PCM and the
BCM communicate this information over the Class 2 serial data line The BCM receives an A/C request signal from the heater A/C control assembly and
transmits this signal to the PCM in order to engage the A/C clutch.
Audible Warnings
The BCM determines the priority of the chime requests and the highest priority chime request is activated. The functions which cause the audible
warning to be activated by the BCM are listed from lowest to highest priority:
1. Automatic door lock-delayed locking verification
2. Automatic door lock-programming option notification
3. Check gauges
4. Headlights left on
5. key left in the ignition
6. Oil life reset
7. Park brake on
8. Tire Inflation Monitoring System (TIMS) reset
9. Turn signal left on
10. Seatbelt not fastened
Only 1 alarm may be on at a given time. For simultaneous chime conditions, the chimes have the priority level as listed. For simultaneous chime
conditions, the BCM completes all of the pending low priority alarms after completing the higher priority alarms.
Check Gauges
The check-gauges alarm sounds 3 tones, at a rate of 50 tones per minute, once per ignition cycle (once per each indicator transition to active) when any
of the following indicators become active, the engine is running and more than 5 seconds have elapsed since the engine began running:
^
ABS
^
BRAKE
^
Oil Pressure
^
Coolant Temp Hot
^
Low Fuel Level
^
LOW OIL
^
LOW TIRE PRESSURE (Oldsmobile) / CHECK TIRE PRESS (Pontiac)
^
LOW Washer Fluid
^
CHANGE OIL
^
SERVICE VEHICLE SOON
^
Volts
Headlamp on Warning System Description and Overview
The headlamps ON alarm sounds at a rate of 300 tones per minute when the following conditions are true:
^
The ignition switch is off.
^
The driver door is open.
^
The parklamp switch is active.
The alarm deactivates when any one of the above conditions changes.
Key In Ignition
