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Home >> Cadillac >> 2009 >> STS Base, 4.6 A, AWD >> Repair and Diagnosis >> Accessories & Equipment >> Anti-Theft Systems >> Keyless Entry System And Remote Functions >> Diagnostic Information and Procedures >> DTC B3121 >> Circuit/System Description
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Circuit/System Description

The rear compartment keyless entry antenna is used to establish low frequency (LF) communications with the keyless entry transmitter. As a vehicle with a closed rear compartment lid is approached with a keyless entry transmitter, known as an electronic key, and the rear compartment lid release switch is pressed, the keyless entry antenna transmitter broadcasts a challenge to the transmitter in an approximate 1 meter range. If the response from the transmitter via radio frequency (RF) is valid, the latched rear compartment will be passively unlocked/unlatched, allowing the rear compartment area to be opened.