Keyless Entry Transmitters

WARNING: This page is about a different car, the 2010 Buick LaCrosse. However, it is still accessible from the selected car via links, so may be relevant.

The keyless entry transmitters are used to passively:

Lock, unlock, release trunk, and start vehicle.

The keyless entry transmitters are used to actively:

Lock, unlock, locate vehicle via panic/locator, release trunk, and remote start vehicle.

By operating any of the exterior door handles, a nearby programmed transmitter is challenged by a keyless entry antenna. The transmitter will passively send a request to the BCM. The BCM will interpret this communication and either allow entry into the vehicle or deny it.

This is accomplished by the transmitter sending a radio frequency to the antenna that has a direct link to the body control module (BCM). The BCM interprets the signal and activates the requested function or request the appropriate ECU to activate the function via a serial data message.