Headlight issue

2012 VOLKSWAGEN PASSAT
120,000 MILES • 4 CYL • AUTOMATIC
Avatar
CHRSRAM44
  • MEMBER
  • 7 POSTS
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.
Dec 11, 2019 at 3:25 AM
Advertisement
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,855 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 enlarge)
Attached Media
Attached Media
Attached Media
Attached Media
Dec 12, 2019 at 12:34 PM
Avatar
CHRSRAM44
  • MEMBER
  • 7 POSTS
Hey Ken. thanks for the reply. seems like this is the route I'm going to take . If you could , can you please explain how the the module turns the lights on ? And why I'm receiving power on both wires ?
Dec 12, 2019 at 5:27 PM
Advertisement
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,855 POSTS
Are you getting power at the brown wire or?

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Let me know
Dec 13, 2019 at 11:17 AM
Avatar
CHRSRAM44
  • MEMBER
  • 7 POSTS
Yes, I am receiving ground on the brown wire.
Dec 13, 2019 at 12:16 PM
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,855 POSTS
Are you getting power at the yellow and blue and the yellow and black on both headlight bulbs? Headlights on.
Dec 16, 2019 at 10:28 AM