Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Rear Demist
The rear window defroster (9/2) is activated by pressing the switch on the climate control module (CCM) (4/6). The climate control module (CCM) transmits the data to the central electronic module (CEM) (4/56) via the CAN network.
The central electronic module (CEM) checks to ensure that the defroster start conditions are fulfilled. If so, the central electronic module (CEM) activates the relay (2/82) located on the rear relay box and the defroster is supplied power via the relay.
Automatic activation of the rear demist (9/2) can be set in the climate settings in the menu for the Infotainment control module (ICM) (3/281). Rear demist starts in connection with starting the engine and an outdoor temperature below +9 Β°C.
On activation of auto defrost rear in the climate settings the Infotainment control module (ICM) transmits to the central electronic module (CEM) that auto defrost rear has been activated. The central electronic module (CEM) saves the value and responds to the Infotainment control module (ICM) that auto defrost rear is activated, which means the Infotainment control module (ICM) checks the option in the climate settings.
The central electronic module (CEM) also transmits a request via the Control area network (CAN) to the climate control module (CCM) to light the LED in the switch.
When the function is switched off, either by pressing the switch on the climate control module (CCM) or that auto defrost rear switches off the function, the LED in the switch on the climate control module (CCM) goes out.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.