GM Service Manual Online
For 1990-2009 cars only

Body Control Module (BCM)

Scan Tool Output Control

Additional Menu Selections

Description

Daytime Running Lamps

Light Test

The BCM actuates the DRL relay for 5 seconds when you select ON. The Daytime Running Lamps should illuminate for 5 seconds.

Delay Accessory Bus

Miscellaneous Test

The BCM commands the retained accessory power (RAP) relay on for 5 seconds when you select ON. The RAP relay control components should operate for 5 seconds.

Door Lock

Door Lock Test

The BCM pulses the power door lock relay when you select ON. All doors should lock.

Driver Door Unlock

Door Lock Test

The BCM actuates the LT door unlock relay when you select ON. The passenger door should unlock.

Exterior Lamps

Light Test

The BCM provides battery positive voltage to the PARK LAMPS relay coil and the HEADLAMP relay coil when you select ON. The exterior lamps output should be active for 5 seconds.

Front Fog Lamps

Light Test

The BCM actuates the FOG LAMP relay for 5 seconds when you select ON. The front fog lamps should illuminate for 5 seconds.

Fuel Door Release

Miscellaneous Test

The BCM pulses the fuel door release actuator when you select ON. The fuel door should open.

High Beams

Light Test

The BCM actuates the HIGH/LOW BEAM HEADLAMP relay for 5 seconds when you select ON, while the low beam headlamps are on. The high beam headlamps should illuminate for 5 seconds.

Horn

Miscellaneous Test

The BCM actuates the horn relay for 5 seconds when you select ON. The horn should activate for 5 seconds.

Inadvertent Power Output

Inadvertent Power

The BCM deactivates the inadvertent power relay when you select OFF. The foot well, IP compartment, rear compartment, vanity mirror, and courtesy lamps should be inoperative for 5 seconds.

Interior Lamps

Light Test

The BCM actuates the COURTESY relay for 5 seconds when you select ON. The foot well, and courtesy lamps should illuminate for 5 seconds.

Low Beams

Light Test

The BCM actuates the HEADLAMP relay for 5 seconds when you select ON, while the Exterior Lamps control is active. The low beam headlamps should illuminate for 5 seconds.

Parking Lamps

Light Test

The BCM actuates the PARK LAMPS relay for 5 seconds when you select ON, while the exterior lamps control is active. The park lamps should illuminate for 5 seconds.

Park Relay

Miscellaneous Test

The BCM deactivates the PARK Relay for 5 seconds when you select OFF. This should allow the trans axle to be shifted out of park without depressing the brake pedal.

Passenger Door Unlock

Door Lock Test

The BCM actuates the door unlock relay when you select ON. The passenger door should unlock.

Rear Defogger

Miscellaneous Test

The BCM actuates the rear defogger relay for 5 seconds when you select ON. The rear defogger relay should operate for 5 seconds.

Rear Fog Lamps

Light Test

This parameter is not used.

Reverse Relay

Miscellaneous Test

The BCM actuates the REVERSE relay for 5 seconds when you select ON. The backup lamps should illuminate for 5 seconds.

Trunk Release

Miscellaneous Test

The BCM pulses the release actuator of the rear compartment lid when you select ON. The trunk should open.