Wake-Up State

The following wake-up signals will turn ON the BCM. The BCM may then begin active control and/or monitoring of certain devices:

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:

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:

Ambient Level Sensor

The ambient light level sensor has the following 2 states:

If the headlamp switch is set to AUTO while in the LIGHT state, the following components will remain fully bright:

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:

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:

Daytime Running Lamps (DRL) and Auto Headlamps

LIGHT State

The daytime running lamps (DRL) turn ON when the following conditions exist:

If you set the park brake, the DRLs will turn OFF. When you release the park brake, the DRLs will turn ON.

The following actions occur if the headlamp switch is set to the PARK LAMP position:

The following actions occur if the headlamp switch is set to the HEADLAMP position:

The following actions occur if the headlamp switch is set to the HEADLAMP position and the HIGH/LOW beam switch is toggled:

If the headlamp switch is set to the AUTO position and the and the ambient light level conditions change to DARK for 15 seconds, the BCM will turn ON the headlamps.

DARK State

The following actions occur is the headlamp switch is set to the AUTO, PARK LAMP or HEADLAMP position:

The following conditions exist if the ignition switch is in the OFF position and the park brake is set:

If you turn the ignition switch to the RUN position, the auto headlamps are defeated. If you release the park brake, the auto headlamps will function. If you set the park brake again, the headlamp function will not change.

If the headlamp switch is in the AUTO position and the ambient light level conditions change to LIGHT for 20 seconds, the BCM will turn OFF the headlamps.

Front Fog Lamps

The front fog lamps are a controlled option of the BCM. The BCM will command the fog lamp relay ON if the following actions occur:

The front fog lamp relay will turn the front fog lamps ON. The front fog lamp switch is a momentary switch. Only one transition occurs each time the front fog lamp switch is pressed. Press the front fog lamp switch in order to turn ON the front fog lamps. Toggle the HIGH/LOW beam switch in order to toggle the front fog lamps ON/OFF.

Passlock™ System

The Passlock™ theft deterrent system is designed to prevent vehicle operation if an incorrect ignition key is used to start the vehicle. The ignition key will allow the lock cylinder to turn. The Passlock™ sensor, which is located inside of the ignition switch assembly, sends a code to the BCM. If the BCM receives the correct code from the Passlock™ sensor, the BCM will send a password to the vehicle control module (VCM) or the powertrain control module (PCM). The message will allow the vehicle to start. Refer to Theft Deterrent for more Passlock™ system information.

Battery Rundown Protection

The battery run down protection provides protection against the following conditions:

The battery run down protection will also protect the battery against being run down from the courtesy lamp circuit to a level that will prevent the vehicle from starting. The BCM will turn OFF the courtesy lamp circuit when the following actions occur:

Complete one of the following actions in order to return the BCM to normal operation when the battery run down protection turns OFF the interior lamps:

Inadvertent Power Relay

The BCM turns OFF the inadvertent power relay after 20 minutes in order to preserve the battery power. The 20 minute timer starts after any one of the following actions occurs:

If any one of the following inputs reoccur during the 20 minute timer period, the timer is reset to 20 minutes:

Retained Accessory Power (RAP)

The RAP feature allows the following components to be operated after the ignition switch is turned from the RUN position to the LOCK position:

The RAP operates if the vehicle battery voltage is above the minimum voltage threshold when the ignition switch is in the OFF position.

The above components will be turned off when either of the following actions occurs:

Refer to Retained Accessory Power System.

Illuminated Entry

The interior lights will illuminate for 15 seconds if any of the following actions occurs:

Interior Illumination

The interior lights will illuminate continuously if the following occurs:

Exit Lighting

The interior lights will illuminate for 40 seconds when the ignition key is removed from the ignition cylinder.

Power Door Lock/Unlock Function

The BCM is responsible for energizing the driver door unlock relay. The driver door unlock relay is energized whenever the BCM receives a command from any of the DOOR LOCK/UNLOCK switches and an input from the RFA module on the RFA serial data line.

Door Lock/Unlock Switch Function

The driver door LOCK/UNLOCK switch and the passenger door LOCK/UNLOCK switch are inputs to the BCM. The BCM will command the driver door unlock relay to unlock the drivers door according to the state of the relevant switch.

Lockout Prevention

The lockout prevention feature is activated when the following actions occurs:

This feature will lock the doors and unlock the driver door.

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:

Refer to Audible Warnings Description in Instrument Panel, Gauges and Console.

Headlamp Reminder

A chime will sound when the following conditions exist:

The headlamp reminder chime will not sound if the following conditions exist:

Refer to Audible Warnings Description in Instrument Panel, Gauges and Console.

Seat Belt Reminder

A chime will sound for 6 seconds when the following actions occur:

The seat belt telltale on the instrument panel cluster (IPC) will also turn ON.

Refer to Audible Warnings Description in Instrument Panel, Gauges and Console.

Turn Signal Reminder

A chime will sound when the right or left turn signal is turned ON for more than 0.75 miles. The chime will be synchronous with the turn signal flasher.

Refer to Audible Warnings Description in Instrument Panel, Gauges and Console.

Driver Warning Telltales

The BCM sends requests to the IP cluster in order to turn the IPC telltales ON or OFF. These requests are sent on the Class 2 serial data line. If the IPC cannot communicate with the BCM via Class 2, the IPC will turn the security telltale ON steady. The following messages are sent by the BCM to the IPC:

Lighting Control

Exterior Lighting Control

The BCM may turn ON some of the exterior lighting independently of the exterior lighting system. The vehicle lighting system controls the same lighting components. The following list indicates which exterior lighting components the BCM may turn ON:

Interior Lighting Control

The BCM may turn ON some of the interior lighting independently of the interior lighting system. The vehicle lighting system controls the same lighting components. The BCM controls the following interior lamps:

The courtesy lamps are enabled by the discrete input to the BCM, from the following components:

Segment Inspection

The IPC illuminates in order to verify that all of the segments of the telltale displays are operating correctly. The turn signal indicators do not turn ON during this inspection. Do not attempt further diagnosis unless all of the segments appear. Further diagnosis could lead to misdiagnosis. If any portions or segments of the IPC displays are inoperative, first diagnose the IPC.