Rear Window Heater, Basic Function - GF67.29-P-2006A

Model All (4xWD) 

Model All (CAR) 

Courtesy of MERCEDES-BENZ USA

Sample illustration of rear window heater 

Overview 

This document contains information on:

• General 
• Function requirements 
• Function 
  • Actuation 
  • Speed-dependent actuation 
  • Temperature-dependent actuation 
  • PRE-SAFE® 

General 

In the case of the rear window heater, a heater with which the rear window can freed from condensation or ice is involved. Fine heating wires are embedded in the glass with which the rear window is heated so that the pane no longer fogs up.

Function requirements 

• Engine running or drive train operational.

Function 

The rear window heater consists of multiple conductor tracks on the rear window. When a voltage is applied, these conductor tracks heat up due to the electrical resistance.

Actuation 

The request for the rear window heater comes among other things from the following:

• The air conditioning control panel (via a LIN connection)
• The touchscreen (via a CAN connection)
• The lower control panel (via a LIN connection)
• The engine control unit (via a CAN connection)
• The head unit (via a CAN connection)
• The Electronic Stability Program control unit (via the FlexRay)
• The overhead control panel (via a LIN connection)
• The outside temperature sensor

Depending on the vehicle, the request is passed on by the signal acquisition and actuation module or by the rear signal acquisition and actuation module to the rear window heater.

Speed-dependent actuation 

The Electronic Stability Program control unit also passes on the vehicle speed to the rear window heater.

Temperature-dependent actuation 

The rear window heater is supplied with information on the interior temperature via the overhead control panel control unit and with information on the outside temperature via the outside temperature sensor.

PRE-SAFE® 

As part of the PRE-SAFE® function, the rear window heater is switched off in the case of an accident. The request comes in this connection from the Electronic Stability Program control unit.

	Component descriptions
	Rear window heater, component description	Model 223	GF67.29-P-5001A
		Model 243	GF67.29-P-5001B
		Model 206	GF67.29-P-5001C
		Model 297	GF67.29-P-5001D
		Model 295	GF67.29-P-5001E
		Model 296	GF67.29-P-5001G
		Model 254	GF67.29-P-5001H
		Model 464	GF67.29-P-5001J
		Model 214	GF67.29-P-5001K
		Model 294	GF67.29-P-5001N