Circuit Description

The Instrument Panel Integration Module (IPM) receives input from the twilight delay switch in headlight switch. IPM supplies ground for the switch through the sensor return. Resistance varies 0-40,000 ohms as switch is operated, and voltage input to IPM changes.

Twilight sentinel is considered off when resistance of twilight delay switch is less than 1000 ohms. When twilight sentinel is on, the Dash Integration Module (DIM) will automatically control the turning on and off of headlights and park lights depending on ambient light conditions.

IPM determines length of time to keep exterior lights on after vehicle is turned off, if exterior lights have been automatically turned on. IPM sends a message via the Class-II serial data line to DIM indicating how long, in 10 seconds increment, the exterior light should be kept on. Length of time exterior lights can be kept on varies from a few seconds for up to 3 minutes.