Cigarette Lighter Battery Charging Function
A trickle charger can also be connected to the cigarette lighter. However, the cigarette lighter is supplied by the body-zone consumer isolation circuit (VA-K) via a relay.
If the "terminal R Off" signal is present for more than 60 minutes, that relay will be switched off by the consumer shutdown function. That would mean that a charger connected to the cigarette lighter would be disconnected from the battery.
To prevent this, the consumer shut-down function can be deactivated. This is performed by the following procedure:
Slide the battery switch off and on again twice within two seconds. Starting with the battery switch in the ON position, switch to OFF, Switch ON, Switch OFF and end with the switch in the ON position. Do this within 2 seconds, an the trickle charger can be used to charge the battery through the cigarette lighter.
The function is cancelled by: "terminal 15 On", switching the battery switch from "OFF" to "ON" or failure of the battery voltage to reach 12.6 V after 6 hours of charging.