Rear Demist

WARNING: This page is about a different car, the 2010 Volvo V70, 2009 Volvo V70, and 2008 Volvo V70. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Rear Demist

Courtesy 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

above +7°C: activated for 12 minutes and then switched off.
+7°C to -15°C: activated constantly for 20 minutes - it then switches to pulsing, 5 minutes activated and 1-10 minutes deactivated. The time it is deactivated is linearly dependent on the temperature.
below -15°C: activated for 20 minutes, then pulsing 5 minutes activated and 1 minute deactivated.

There are diagnostics for the relay and switch.