Transponder Key: Description

Fig 1: Sentry Key Immobilizer Transponder

Courtesy of DAIMLERCHRYSLER CORP.

Each ignition key used in the Sentry Key Immobilizer System (SKIS) has an integral transponder chip. See Fig 1. Ignition keys with this feature can be readily identified by a gray rubber cap molded onto the head of the key, while conventional ignition keys have a black molded rubber cap. The transponder chip is concealed beneath the molded rubber cap, where it is molded within a plastic mount into the head of the metal key. In addition to being cut to match the mechanical coding of the ignition lock cylinder, each new Sentry Key has a unique transponder identification code permanently programmed into it by the manufacturer. The Sentry Key transponder cannot be adjusted or repaired. If faulty or damaged, the entire key must be replaced.