ABS EPS and traction error when headlights on

[michaelpappas]

I started to notice that my abs traction and eps warning lights came on intermittently. I decided to start with the easiest repair end replaced my brake pedal sensor. This didn't help. I haven't had the time to tackle looking into the wheel sleep sensors. In the interim I have noticed some other oddities and I'm curious is anyone has any insights.
These three lights only come on when the headlights are on. I'll drive multiple days in a row without needing the headlights and these error lights don't come on.
The car engine won't turn off if I have my foot on the brake and the headlights are still on. I can remove the keys from the ignition and the engine will continue running. If I release the brake OR turn the headlights off with key pulled out of the ignition the car will then turn off.
If these lights are on and I shift into park the car won't allow me to move out of park until I turn the car off and back on.
When I restart the car with the above scenario I will get a "start error" message on the odometer unless I take the keys out and turn the headlights off.

Given all of these electrical peculiarities it seems like this is less a mechanical/sensor issue and more so some wiring gremlin. Does anyone have familiarity with issues like these or have any ideas on where to start? Thank
Michael

 

[Cheyenne]

It will almost certainly be a fault with your tail lights!

Either you have a short on the metal tracks on the rear of one of your tail light units or you have an incorrect Brake/Tail light bulb installed. The power is 'backfeeding' from the side light circuit to the brake light circuit and keeping the ignition 'Live'.

Try unplugging one then the other of your tail lights and see if you can isolate the problem.

Keith.

 

[michaelpappas]

It will almost certainly be a fault with your tail lights!

Either you have a short on the metal tracks on the rear of one of your tail light units or you have an incorrect Brake/Tail light bulb installed. The power is 'backfeeding' from the side light circuit to the brake light circuit and keeping the ignition 'Live'.

Try unplugging one then the other of your tail lights and see if you can isolate the problem.

Keith.

Long story short, i kept burning brake light bulbs on my left tail light. The brake light bulb will have both elements lit when the headlights are on and eventually burn out. I thought it might be the tail light circuit so i replaced that but the brake light element is still continuously lit when the headlights are on. So it would seem that the issue is that the brake light is somehow getting current from the part that get illuminated when the headlights are on. Any tips on tracing the issue back to the source? Does the wiring from the tail lights trace back to under the driver's seat?

 

[Cheyenne]

I would start by checking the ground connection of the left hand headlight as that seems to be where the trouble is originating. The headlight is most likely using the side light circuit as its ground.

Keith.

 

[autostaretx]

Full 2006 service manual here: http://diysprinter.co.uk/reference/2006-VA-SM.pdf
2003 and 2004 here: http://diysprinter.co.uk/reference/

Full wiring diagrams form section 8W of the manuals, section 8W-91 is a locator map of connectors and ground points.
(the 2006 version is the most complete)

--dick

 

[michaelpappas]

Fixed!

I looked into the front headlights and after fiddling with the wiring harness that comes into the headlight and the turn signal/running light bulb the problem went away. the turn signal bulb was loosing a lot of its orange coating. My guess is that the coating was maybe flaking off and closing the connection between the running lights and the turn signal. I say this because before this issue was resolved i noticed that when i stepped on the brake with the headlights on the opposite headlight's turn signal would light up when the brakes were engaged. I could be totally wrong but that's my best guess. The issue of the car not turning off when the headlights and brakes were engaged, lights were on, and keys were out also cleared up. All in all this seems like some bad wiring design. The fact that a bad ground and/or back feeding current could make such a crazy chain of events and also not show up during and OBDII scan is pretty frustrating. Thanks for all of your help guys!

 

[rfletcher]

I had this happen to me and agree with the first diagonsis. I un-plugged all of my lights, cleaned all of the contacts, added some di-electric grease to everything and put it all back together. I also pulled out all of the bulbs and cleaned the metal contacts where the bulb seats as well. I used some fine sand paper to get the bare metal showing again. The problem went away and never returned. Super easy and cheap to do, so worth a shot.