Heated rear window, function - GF67.29-P-0003T

MODEL 211.0/ 2/ 6

15.03.07

The document has been updated to this date and will no longer be subject to revision.

Fig 1: Heated Rear Window Function Chart

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Function

When the heated rear window button on the AAC control and operating unit (N22) or comfort AAC control and operating unit (N22/7) is pressed, the heating wires on the heated rear window (R1) are supplied with power via the passenger compartment CAN bus and the rear SAM control unit with fuse and relay module (N10/2) and the heated rear window relay is activated. This is displayed by the function LED. Pressing again cancels the function.

Automatic switch-off of the function is time-controlled. If the rear SAM control unit with fuse and relay module (N10/2) recognizes undervoltage during the heating phase, the function is switched off and the function LED flashes. At a vehicle electric network voltage (U) > 11.8 V, the function continues, the function LED again burns constantly.

The heated rear windows are supplied with power according to the following

Criteria:

At outdoor temperatures of > 5°C, the switch-on duration is of 6 min.
At outdoor temperatures of < 5°C, the switch-on duration increases infinitely up to 12 min. at on outdoor temperature of = -7°C.
At outdoor temperatures of < -10°C, the switch-on duration changes until an interior air temperature (N70b1) of 5°C is measured
At a vehicle speed (V) of 50 km/h, the heating time increases by 1 minute per 10 km/h.

On model 211.2, the upper visible wires are antennas they are not heated

The speed signal (V) is read in by the instrument cluster (A1) and transmitted to the rear SAM control unit with fuse and relay module (N10/2) via the passenger compartment CAN bus.

The on-board voltage (U) is read in by the EIS control unit (N73) and transmitted to the rear SAM control unit with fuse and relay module (N10/2) via the passenger compartment CAN bus.

The interior temperature is read in by the in-car temperature sensor (N70/b1) and transmitted to the rear SAM control unit with fuse and relay module (N10/2) via the overhead control panel control unit (N70) and the passenger compartment CAN bus.

The outdoor temperature is read in by the outside temperature indicator temperature sensor (B14) and transmitted to the rear SAM control unit with fuse and relay module (N10/2) via the left front SAM control unit with fuse and relay module (N10/1) and the passenger compartment CAN bus

Heated rear window, networking of components		GF67.29-P-0003-02T
Heated rear window (RWD), location of components		GF67.29-P-0003-01T
Rear SAM control unit with fuse and relay module, location/task	Model 211.0/6	GF54.21-P-4130T
	Model 211.2	GF54.21-P-4130TA
Overhead control panel control unit, location/task/design		GF82.20-P-4110T
Electronic ignition switch control unit, location/task		GF80.57-P-4120T
Driver-side SAM control unit with fuse and relay module, location/task/design		GF54.21-P-4109T
In-car temperature sensor with ventilation blower, location/task/function		GF83.57-P-2107T
Outside temperature sensor, location/purpose/function		GF83.57-P-2110T