LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Volvo >> 2009 >> V70 >> Repair and Diagnosis (Single Page) >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Alarm, Electrical Control Modules, Brakes, Brake Control Module (BCM) - Design And Function >> Central Electronic Module (CEM) >> Design >> Rear Demist
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Rear Demist

Fig 1: Identifying Rear Demist
GLL161314Courtesy of VOLVO CARS CORPORATION

There are heating loops in the glass for demisting and to prevent ice from forming. The loops heat up when they are supplied with power. The power supply is via a relay on the central electronic module (CEM).

Rear demist is controlled via a switch located on the climate control module (CCM) it can also be activated by selecting auto defrost rear, on the climate settings in the menu for the Infotainment control module (ICM).

Automatic rear demist starts when the engine starts and the outdoor temperature is below +9 °C.

In order to switch off the function before it is switched off automatically press in the switch again. Automatic switching off of the rear demist is dependent on the outdoor temperature according to

There are diagnostics for the relay and switch.