Courtesy Lamp Circuit

WARNING: This page is about a different car, the 2009 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.

The courtesy lamp circuit includes the courtesy lamps located under each outboard end of the instrument panel and, depending upon the selected vehicle options may include either the front dome lamp located on the headliner between the sun visors near the windshield header or the map/reading lamps located in the mini overhead console near the windshield header, the second row dome/reading lamps located in the headliner near the roof rail above each rear door opening, the cargo lamp located in the headliner near the center of the rear header above the cargo area, and the vanity lamps located in the sun visors. The lamps in the courtesy lamp circuit are provided with battery voltage and ground by the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN) using internal drivers through a courtesy lamp driver circuit and two ground circuits based upon electronic ajar switch status message inputs received from the Totally Integrated Power Module (TIPM) over the Controller Area Network (CAN) data bus. The EMIC also uses electronic left multi-function switch and ignition switch status message inputs received from the Steering Control Module (SCM) over the Local Interface Network (LIN) data bus to control these outputs.

After all of the ajar switch inputs to the TIPM transition to open, the EMIC will keep the courtesy lamps illuminated for about 30 seconds, then fade the lamps to OFF (theater dimming) over about 3 seconds. The EMIC also provides courtesy lamp operation based upon the electronic left multi-function switch status messages received from the SCM, and provides an illuminated entry feature in response to certain electronic message inputs received from the Sentry Key REmote Entry Module (SKREEM) (also known as the Sentry Key Immobilizer Module/SKIM or the Wireless Control Module/WCM) and the Occupant Restraint Controller (ORC) over the CAN data bus. A courtesy lamp DEFEAT mode based upon an electronic left multi-function switch status message received from the SCM will cause the EMIC to override normal courtesy lamp operation based upon any ajar switch inputs to the TIPM.

For those lamps on the courtesy lamp circuit with independent switching such as the front dome lamp, the optional reading lamps, the second row dome/reading lamps, the cargo lamp and the vanity lamps, the EMIC provides a second battery feed to the switches using another internal driver through a separate courtesy lamp load shed circuit (also known as the convenience circuit). The EMIC provides a battery saver (load shedding) feature for all courtesy lamps, which will automatically turn these lamps OFF if they are left ON for more than about eight minutes with the ignition switch in the OFF position.