Ignition Node Module

In vehicles without PEKG, the SKIS circuitry transmits RF signals to, and receives RF signals from the Sentry Key transponder through the tuned Sentry Key antenna enclosed within the molded plastic antenna housing connected to the IGNM. If this antenna is not mounted properly around the IGNM lock cylinder housing, communication problems between the SKIS control circuitry and the transponder may arise. These communication problems will result in Sentry Key transponder-related faults.

When the status of the ignition switch is ON, the SKIS control circuitry transmits an RF signal to the transponder in the ignition key. The SKIS then waits for an RF signal response from the transponder. If the response received identifies the key as valid, the SKIS control circuitry sends a valid key message to the PCM over the CAN-C data bus. If the response received identifies the key as invalid, or if no response is received from the key transponder, the SKIS sends an electronic invalid key  message to the PCM which prevents the engine from starting.