Chevrolet Sonic Repair Manual: Rear Window Defogger Description and Operation
- Rear Window Defogger System Components
-
The rear window defogger system consist of the following components:
- The HVAC control module
- The body control module (BCM)
- The rear defogger relay
- The rear window grid
- Driver outside rearview mirror
- Passenger outside rearview mirror
- 30A fuse
- Rear Window Defogger Operation
-
The BCM supplies 12?€‰V signal to the rear window defogger switch signal circuit to the HVAC control module. When you depress the rear window defogger switch, the rear window defogger switch pulls the signal circuit low. The BCM interprets as a request for the rear window defogger system. The BCM enables the rear window defogger system by supplying voltage to the rear defogger relay coil. The relay coil supply voltage is also spliced off internally in the BCM to the supply voltage circuit of the rear window defogger indicator. The rear defogger relay is energized and the rear window defogger indicator is illuminated. With the relay energized, battery positive voltage is allowed from the relay switched input through the switch contacts and out the relay switched output to the rear window defogger grid.
When you start the engine and press the rear window defogger switch for the first time, the defogger cycle lasts for 15?€‰minutes. Further operation results in 7.5?€‰minute defogger cycles. The rear defogger feature will not time out if vehicle speed is above 80?€‰km/h (50?€‰mph). The defogger cycle resets to 15?€‰minutes when you cycle the ignition to the OFF position and then to the ON position.
- Heated Mirrors
-
The heated mirrors are also controlled through the rear defogger relay. Whenever the rear window defogger is turned on battery voltage is supplied to the mirror heater elements through the left and right mirror heater element control circuits.
Side Window Defogger Outlet Grille Replacement
Side Window Defogger Outlet Grille Replacement
Callout
Component Name
1
Side Window Defroster Outlet Grille (Qty:?€‰ ...
Horn
...
Other materials:
Airbag Steering Wheel Module Coil Centering
Note: If a double wire harness strap is installed onto the wire
harness assembly and steering column, the original holder for the wire strap(s)
MUST be reused during installation.
Remove the wire harness strap(s) where necessary.
Caution: The new SIR coil assembly will ...
Knock Sensor Replacement
Knock Sensor Replacement
Callout
Component Name
Preliminary Procedures
Disconnect battery negative cable. Refer to
Battery Negative Cable Disconnection and Connection.
Raise and support the vehicle. Refer to
...
Torque Converter Removal
Torque Converter Removal
Callout
Component Name
1
Lock Pin
Warning: Lock pin must be secured into the bench fixture to
hold the transmission and prevent bodily injury.
Note: Ensure the DT ...
0.0082