Rear window defroster function - GF67.29-P-0003A

MODELS 202 as of 1.6.97, 208, 210.081 /281 (except 208.4), 210 (except 210.081 /281) as of 1.3.97 

Rear window defroster network 

Fig 1: Identifying Rear Window Defroster Function

The rear window defroster function is switched on if the rear window defroster switch  in the push-button control module for automatic heater (N18) or air conditioning (N19) or automatic air conditioning (N22) is pressed. The switch signal is applied with voltage coding to an input of the signal acquisition and actuation module (SAM) (N10/1)  . The SAM (N10/1) transmits the "rear window defroster ON" command via CAN to the pneumatic system equipment (PSE), combination functions (A37)  . In addition, the SAM (N10/1) initializes the function LED in the rear window defroster switch.  The PSE (A37) actuates the rear window defroster via a load relay.

The SAM (N10/1) transmits the "rear window defroster OFF" signal to the PSE (A37) if

• circuit 15R off is detected,
• undervoltage < 11 V is detected,
• an ATA alarm is triggered,
• the rear window defroster switch is actuated again,
• at the latest, however, following the expiry of a delay period of 12 min.

The PSE (A37) then switches the rear window defroster off  . The function LED is extinguished. In the event of a cutout due to undervoltage, the function LED in the switch flashes on and off at a frequency of 1.5 Hz.

In the case of model 210.2, the heater wire of the rear window defroster is used as a glass breakage sensor  for the interior motion sensor.