The Onboard Voltage Control unit (J519) lives behind the dash on the drivers side roughly above the drivers right foot. It supplies voltage to many things including:
- Cruise control
- Alternator load management
- Heated rear window
- Mirror heating
- Interior lights
- Reverse light
- Hazard lights
- Screen washers
- Bonnet switch
- Door switch position recognition
- Tow bar
Failed wipers are quite a common fault that can be caused by the J519 but not necessarily the only one, A failing J519 can produce it’s own fault code or can cause other fault codes on the electrical system depending on the type of failure.
The bad news is the VW retail price is £380 + VAT. Second hand units go on ebay for around £100 but there is no guarantee that they will work fully. The suddenly failing wipers is just one common fault you could inherit.
If you buy a new or second hand J519 it will need coding. A dealer or anyone with VCDS can do this. If it will still communicate, get the coding from the old unit via diagnostics. It’s easier if you already have the correct coding ready for the new unit.
On the facelift vans (2010 on) the J519 is combined with the comfort module which used to be under the driver’s seat to become the body control module (BCM).
If you have any problems with wipers, horn, indicators etc start by checking all fuses before buying anything. Sometimes systems have more than one fuse so check every one with a meter or test lamp. There is a second fuse box under the bonnet down beside the battery.
If all checks revert back to the module, then nothing to worry about we are able to repair these units,
Simply use this service to send your module in for repair.