Rear Integration Module (RIM)
Load Shed Lvl.2 R. Defog.: The scan tool displays Enabled/Disabled.
The scan tool displays Enabled, when system voltage is low. The RIM cycles
the rear window defogger ON at 50 percent of a cycle and OFF at 50 percent
of the cycle.
Rear Defog Relay: The scan tool displays On/Off. When
the rear window defogger is enabled, the HVAC control module sends
a class 2 message to the RIM to enable the rear defogger relay. The
RIM energizes the rear defogger relay by grounding the control circuit of
the rear defogger relay, which the scan tool displays as On.