Rear Window Defogger

The HVAC programmer receives the rear defog request from the heater and A/C control assembly. The HVAC programmer will then send a Class 2 message to the body control module (SBM). The SBM will control the rear defog on/off status and the amount of time that the rear defog is on. The SBM will communicate the rear defog status to the HVAC programmer over the Class 2 bus and the HVAC programmer will light the rear defog indicator accordingly.

The heated mirrors are activated when the HVAC programmer receives the rear defog request from the heater and A/C control assembly. The HVAC programmer will then send a Class 2 message to the drivers door module (DDM). The DDM will control the drivers heated mirror on/off status and the amount of time that drivers heated mirror is on. When the Class 2 request is received by the DDM from the HVAC programmer, the DDM will communicate to the passengers door module (PDM) over a simple bus interface. The PDM will control the passengers heated mirror, the on/off status, and the amount of time the heated mirror is on.