Headlight issue

CHRSRAM44

MEMBER
2012 VOLKSWAGEN PASSAT
4 CYL
AUTOMATIC
120,000 MILES

I'm having an issue with my car, one day the low beam headlights began to act funky and then continued to not work at all. I've checked all relays and fuses and everything seems to check out. Taillights and everything else work just fine. When I checked the two wires straight to the low beam bulb, I get power on both wires. When putting the switch on I still have power to both wires (light is not working of course). When I perform the same test for the high beam side. While off it receives power on both wires but when I turned the high beams on I get power in one wire and ground on the other. So my question would be how does this system work? Does the BCM supply a power and ground to turned the headlights on? If so would the module be at fault? I have all the diagrams I need but anything helps. I just want a better understanding how this system works.

5 Replies

KEN L

MASTER CERTIFIED MECHANIC
48,363 POSTS

Hello,

It sounds like the electrical system control module has gone out. Here is how to replace it and the location with the headlight wiring diagrams so you can see how the system works.

Vehicle Electrical System Control Module -J519-
If the vehicle electrical system control module is to be replaced, the work procedure to read out the codes stored in the vehicle electrical system control module must always be performed. Refer to Vehicle Electrical System Control Module -J519-, CODING.

NOTE: It is permissible for the number of connectors to deviate from the figure, depending on the vehicle variants.
CAUTION:
Turn off the ignition and all electrical consumers.
Remove the key.
Removing
-- Remove the lower trim on the driver side. Refer to REMOVAL AND INSTALLATION.

-- Press the catches -arrows- and swivel the vehicle electrical system control module downward.

Fig 2: Identifying Vehicle Electrical System Control Module
GWWN97-11318
Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
View Full-Screen
-- Pull the vehicle electrical system control module downward and opposite the drive direction and remove it from the bracket.

-- Disconnect the connectors.

Installing
Install in reverse order of removal. Note the following:

-- Insert the vehicle electrical system control module first with the back of the module into the bracket and push it up until it audibly latches.

Vehicle Electrical System Control Module -J519-, CODING
-- Code Vehicle Electrical System Control Module -J519-, use the Vehicle Diagnostic Tester.

Check out the diagrams (below). Please let us know what happens.

Images (Click to make bigger)