Operation CHARM: Car repair manuals for everyone.

Principles of Operation

PRINCIPLES OF OPERATION

The vehicle security module (VSM) is on the medium speed controller area network (MS-CAN). The VSM controls the power door lock system. The VSM receives lock/unlock inputs from the door lock control switches. When the VSM receives an lock/unlock command from any door lock control switch, the VSM activates the door lock actuators. The VSM also controls the remote keyless entry (RKE) transmitter lock/unlock and will activate the panic alarm (horn sounding and park lights flashing intermittently in regular intervals) when the panic button on the RKE transmitter is pressed. Refer to Locks.

The VSM receives wireless signal from both the RKE transmitters and the tire pressure monitoring system (TPMS) using the same internal TPMS/RKE antenna located inside the VSM.

The VSM sends an interior lamp request signal the instrument cluster (IC) when the doors are unlocked using the RKE transmitter. All of the ajar signals are monitored by the VSM using the CAN to determine if it should send a signal to IC to turn off the interior lamps when the doors locked using the RKE transmitter. If all of the doors are closed, and the RKE transmitter lock button pressed, the VSM will send a signal to the IC to turn off the interior lamps. If one or more doors are detected open by the door ajar switches input the VSM, then the VSM will not send a signal the IC to turn off the interior lamps and they will stay on.