Info - TrapAlert System

This bulletin is being issued to inform dealers of the TrapAlert system on some Chevrolet Impala's and Monte Carlo's.

The GM TrapAlert system contains the following components:

Some vehicles may be equipped with the GM TrapAlert system. This system will release the deck lid and sound the horn if a combination of a difference in temperature compared to ambient and a movement is detected in the rear compartment by the rear compartment occupant sensor (1).

The rear compartment occupant sensor is connected to battery voltage and ground at all times. When a combination of a difference in temperature compared to ambient and movement is detected by the sensor (2), the body control module (BCM) will command the horn ON for 1 minute, the trunk will then release and the horn will continue to sound for 1 more minute. This process will initialize within 3 minutes of a detect signal from the rear compartment occupant sensor.

If the ignition is in the ON position when the BCM receives the detect signal, the disable switch (1) on the rear compartment occupant sensor will flash.

Important: 

The horn may be stopped by cycling the ignition from OFF to ON. If the ignition is in the ON position when the BCM receives the detect signal, the horn will not sound and the trunk will not release, although the rear compartment occupant sensor lighted disable switch (1) will illuminate.

Because the sensor (2) detects motion and temperature change, there are times you may want to disable the trunk sensor so that the motion of the vehicle or items in the trunk will not command the deck lid to open, such as the following:

The rear compartment occupant sensor can be disabled by pressing and holding the disable switch (1) on the sensor for 2 seconds with the ignition in the ON position. When disabled, the BCM will command the trunk ajar telltale ON for 1 minute with each ignition ON signal while the sensor is disabled. Once the rear compartment is opened, the sensor will reset to an enabled status and resume normal operation.

The sensor can also be enabled inside of the trunk, if disabled, with the ignition ON or OFF by pressing the disable switch (1). If the rear compartment occupant sensor is disabled, the trunk ajar telltale will illuminate for 30 seconds with each ignition ON cycle.

The BCM monitors the status of the rear compartment occupant sensor through the trunk ajar switch signal circuit continuously. If the BCM detects a problem, a DTC will set and the service vehicle soon telltale will illuminate.

Refer to the Body and Accessories - Body Rear End sub-section in the Service Manual for the appropriate service procedures and repair instructions.

Notice: The TrapAlert Rear Compartment Occupant Sensor is not designed to be removed. If the sensor is removed, damage may occur to the retaining clip and the sensor may have to be replaced.

Important: It is not necessary to remove the sensor to perform the diagnostics on the system.

For technical and parts information, call the Technical Assistance Center and reference Preliminary Information (PI) A001640.

For vehicles repaired under warranty, use: