Blinking glow plug light

[joep1234]

Hit a lot of water puddles on the way home this afternoon. The trans started shifting funny (DSG) like it was in sport mode but you could manual shift it all the way up and then the glow plug light started blinking. I can't get it scanned until the AM but was wondering if this has happened to anyone else. I shut it down, pulled the key, then restarted and everything was OK for about 10 minutes and then it started again. Any ideas?

 

[Vince Waldon]

Total guessing game until you get it scanned... water got into something, but what?!

 

[AnotherPerson]

I have the same issue with my pedal when we get a ton of rain. Codes don't help narrow down for me but I'm going to be tracing down the grounds and making sure they are solid.


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[joep1234]

Scanned the car and got a P0571 code for implausible brake switch. I will be getting one tomorrow but my question is why would the glow plug light blink for a brake switch or is this another quirky thing with these cars?

 

[Vince Waldon]

The blinking light just a "fix me right away" malfunction indicator light... about 20 different causes, all of them generally under the heading of "safety".

So, yup, the car was anxious about a bad brake light switch, for safety reasons, and was trying to get your attention with a flashing light.

Only the German engineers who designed 'er know why they chose to flash the glow plug light as opposed the the check engine light for safety concerns, although it may have been because there are safety issues *not* related to checking the engine.

 

[BobnOH]

There is a fair chance all will be fine again once things dry out. Happened to me once or twice. Certain codes, some which trigger the blink may not go away until the car has been run several times with no error.

 

[wonneber]

Scanned the car and got a P0571 code for implausible brake switch. I will be getting one tomorrow but my question is why would the glow plug light blink for a brake switch or is this another quirky thing with these cars?

Before you install the switch check if both rear brake lights work (plus the high mount)
I had that once when both my brake lights burnt out, also after installing LED brake lights.

I think the CEL is only for emissions related failures.
Not sure what a gas car would blink, maybe the parking brake light.

 

[dweisel]

If your brake switch is bad. The cruise control won't work. Check to see if cruise control works.

 

[joep1234]

It didn't work while the code was present. Cleared it this AM and everything is working. I bought a new one today ($8.97) to put in tomorrow. Don't like driving a car that I am afraid that will leave me on the side of the road even if it is adventure driving. After I replace it, I may go ahead and change the bulbs to be on the safe side.

 

[joep1234]

Had one rear tail light burnt out while checking everything over. Also put in new brake switch and didn't expect what happened afterwards. I have had some turbo lag I thought. Take your foot off the brake and it is ready to go. No more turbo lag and shifting quicker. Apparently the ecm was having a hard time figuring what was going on.

 

[joep1234]

more of the same

Its raining again and the trans is acting up again. As stated in my last post I had a burnt tail light bulb and a code for implausible brake switch. Replaced the bulb and switch and all was well. Turned on the head lights going out to get some lunch and the trans didn't want to shift properly and cruise stopped working. With the lights on I could shift the trans out of park without holding the brake. With the lights on, my brake lights and center light lights up. With the lights off the brake lights work normally. Sounds like a bad light switch but open to suggestions.

 

[wonneber]

I wonder if you have a bad ground at the top of the trans, or the one under the battery tray.
Could check the headlight ground also.
I'm thinking power if feeding back from the headlights into the trans through the grounding.
Did you do a scan while you had the problem?

 

[joep1234]

Possible fix.

Yes. My son did a complete scan on the car. The only code was for GP's. No other stored codes for every system in the car. While it was still wet we swapped a known good head light switch and still had the same problem. Started back tracking and took the tail lights out to check the bulbs and while I was applying the brake and turning the lights on and off, we noticed that the 3rd light would light up with the head lights on. Narrowed it down to feed back from the tail light sockets. The bulbs were loose and not getting a good ground. Tightened up the socket and bought 2 new bulbs and everything is back to normal. If it starts acting up again, I will order 2 new bulb sockets.

 

[wonneber]

Bad ground makes sense.
The parking light power has no ground so it grounds backwards through the brake light to the other brake light and it's ground.
If you would have stepped on the brake while the head lights were on that side brake light will go out.

 

[joep1234]

With the head lights on, the only light to light up was the center light. No brake or running lights. But all is well now.