For 1990-2009 cars

### Door Lock System Components

The power door lock system consists of the following components:

• | Driver door lock switch

• | Front Passenger door lock switch

• | Body Control Module (BCM)

• | Relays: Driver Door Unlock -- on vehicles with RFA, Door Unlock, and Door Lock

• | Door Lock fuse 15A

### Door Lock System Controls

The power door lock system can be controlled by any of the following:

• | A power door lock switch activation

• | A keyless entry command -- if equipped with keyless entry

### Driver and Passenger Door Lock Operation

When any of the door lock switches is pressed to the lock position, the BCM door lock/unlock signal circuit changes from an idle voltage of ~3.4 volts to 0.0 volts generating a lock command. The BCM then applies battery positive voltage to the Door Lock Relay, which in turn applies battery positive voltage to the Door Lock Actuator lock circuit of all the Door Lock Actuators. Since the Door Lock Actuator unlock circuits are held to ground through the resting Door Unlock Relay(s), the actuators execute the lock command, locking the doors.

The lock function can also be accomplished by the BCM having received a keyless entry door lock command, if the vehicle is equipped with keyless entry.

### Driver and Passenger Door Unlock Operation

When any of the door lock switches is pressed to the unlock position, the BCM door lock/unlock signal circuit changes from an idle voltage of ~3.4 volts to ~1.7 volts generating an unlock command. The BCM then applies battery positive voltage to the Door Unlock Relay and the Driver Door Unlock Relay when equipped with keyless entry, the relay(s) in turn apply battery positive voltage to the Door Lock Actuator unlock circuit of all the Door Lock Actuators. Since the Door Lock Actuator lock circuits are held to ground through the resting Door Lock Relay, the actuators execute the unlock command, unlocking the doors.

The unlock function can also be accomplished by the BCM having received a keyless entry door unlock command, if the vehicle is equipped with keyless entry. Keyless entry personalization allows the driver door to be unlocked individually before unlocking the passenger doors. When this feature is active, the BCM will require a repeated unlock command to unlock the passenger doors.

### Lockout Prevention

The BCM does not allow the driver door to stay locked when you press LOCK on either door lock switch with the lockout prevention feature active. The BCM activates the lockout prevention feature when the following conditions exist:

• | A vehicle door is open.

| An open vehicle door sends a ground signal to the BCM door ajar switch input.

• | The key is fully inserted in the ignition cylinder.

| Full insertion of the key sends a signal to the BCM key in ignition input.

### Lockout Prevention Override

The BCM overrides the lockout prevention and locks all of the doors. This feature occurs when you press the lock switch on the key fob.

### Last Door Locking

This feature prevents the doors from locking until after all of the doors have been closed for approximately 10 seconds. The BCM activates the last door locking feature when a door ajar signal is present and a door lock switch lock input is received by the BCM.

### Automatic Door Lock/Unlock

The automatic door lock/unlock function is a Vehicle Personalization feature with the following four programmable modes of operation:

1. The automatic door lock feature is disabled.
2. All of the doors lock when the vehicle is shifted out of Park with the ignition ON.
3. All of the doors lock when the vehicle is shifted out of Park with the ignition ON, and all of the doors Unlock when the vehicle is shifted into Park.
4. All of the doors lock when the vehicle is shifted out of Park with the ignition ON, and only the driver door Unlocks when the vehicle is shifted into Park.

For information on programming the automatic door locks, refer to Vehicle Personalization in Personalization.

### Unlock After Air Bag Deployment

This feature will unlock all of the vehicle doors 15 seconds after air bag deployment.