Is VAG-COM required for clearing flashing glow plug indicator?

[madrean]

I recently was pulling my popup trailer with electric brakes. As I pulled into the Bucky's filling station, I could tell that the trailer brakes were staying engaged, and thought they were hung up or something. Turned out that the car was activating brake light output (and my trailer brakes which were wired off one of my brake lights). This was also happening with the car off. Flashing glow plug indicator.

I figured that the brake pedal switch had died, and was causing the fault. I replaced the switch, and now the brake lights are working again (trailer is now disconnected). However, the flashing glow plug light is still blinking.

No faults are showing on my SGII.
2002 Golf with 200k mi. No power or performance changes that I can detect.

So I am wondering
1) Do I have to use VAG-COM to clear the fault?
2) Did wiring the electric brakes directly off a brake light line somehow cause the switch to fail? The brakes had worked fine for about 60 miles..


Thanks,
Mark

 

[grease_pit]

Did I read your post right? Does it really say that you wired the trailer brakes to the brake light wiring on one side of your car? Wiring electric trailer brakes through the brake light circuit on you car would most certainly burn-up the small contacts in your car's brake light switch. Actually, I am surprised that the extra current draw of the trailer's electric brake coils didn't immediately blow the fuse in the brake light circuit (You might want to check to see what size fuse is installed in your cars brake light circuit).

Are you sure the flashing light is in fact the glow plug indicator light. I can't think of any way the failure of the brake light switch would result a flashing glow plug light. Sounds more like two unrelated failures to me.

To answer your question about whether you need VAG-COM to clear the fault...the answer would be no...you will however need VAG-COM to clear the fault code, once you have fixed the fault or problem that is causing the fault code.

 

[40X40]

Scroll to the bottom of this page and click on the threads that you see there.

Bill

 

[madrean]

Yes, grease pit, you read it correctly. Against my better judgement, that is how I powered the brakes. I knew better, and contemplated the excess current, AND I already had a 12V source going back to the hatch. What happened was my older neighbor convinced me it would be okay, even though I really knew it wouldn't be.

It's interesting-- I wonder if the brake switch will cause the brake lights to stay on when it fails, vs not having any brake lights at all?

I've got my VAG-COM cable, now I just need to find my old dinosaur dell laptop... (I use OSX).

Thanks for your reply.

 

[grease_pit]

Yup...the contacts in the brake light switch can weld themselves closed, and that would make the brake lights (and the electric trailer brakes in a scenario like yours) to fail in the on position (energized).
I wish you the best of luck with your old Dell laptop...we also use OSX and I dread it when I have to fire-up the old Dell to run VAG-COM. VAG-COM for OSX would be a great present to find under the christmas tree this year....

 

[TurbineWhine]

I recently was pulling my popup trailer with electric brakes. As I pulled into the Bucky's filling station, I could tell that the trailer brakes were staying engaged, and thought they were hung up or something. Turned out that the car was activating brake light output (and my trailer brakes which were wired off one of my brake lights). This was also happening with the car off. Flashing glow plug indicator.

I figured that the brake pedal switch had died, and was causing the fault. I replaced the switch, and now the brake lights are working again (trailer is now disconnected). However, the flashing glow plug light is still blinking.

No faults are showing on my SGII.
2002 Golf with 200k mi. No power or performance changes that I can detect.

So I am wondering
1) Do I have to use VAG-COM to clear the fault?
2) Did wiring the electric brakes directly off a brake light line somehow cause the switch to fail? The brakes had worked fine for about 60 miles..


Thanks,
Mark

Yes a defective or in your case, a likely welded shut set of contacts, on the brake light switch will cause the glow plug light to flash.

Replace the brake light switch. Use the brake light wire to activate a seperate 30A fused relay to power your trailer brakes with. You should not have to clear any codes with VCDS.

TW

 

[madrean]

The flashing glow plug lamp went away on its own. I have since ordered an electric brake controller.

Now, I need to install an EGT gauge...

Thanks for the replies.

 

[manual_tranny]

FWIW, I regularly hook up two trailers directly to the turn/brake/running lights for many many hours without any problems. LED lights are nice.