How to scan "engine management system?"

Yesterday, while finishing on a 300 mile road trip, I got a flashing glow plug caution light while driving. Page 17 of section 3 of my owner's manual says that this indicates a malfunction of the "engine management system," and, of course, advises having the vehicle be checked by "a certified VW service facility as soon as possilbe." The light was on for 30 miles or so and went off after shutting down and restarting.

Today I scanned the engine and transmission and found no codes. I also tried, but was unable to, connect to engine elct. I, and II.

Does anyone know where, in Vag-Com to look for the stored code, assuming that there is one? I didn't do a full scan because I have a 2001 with the suspected freakish airbag controller that commits suicide when you scan it.

It would normally be under 'engine', but it could also be a non-critical system. Just go through the list with a judicious avoidance of the ABS.

What scan tool/software are you using?

Chances are you need a new brake light switch.

oilhammer said:

What scan tool/software are you using?

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I was using the full version of 704. Since posting, I've updated to 805, but I have not retried to scan it yet.

oilhammer said:

Chances are you need a new brake light switch.

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That's pretty good! At the same time I was also dealing with a failed brake light switch.

The REST of the story is that the brake light switch failed while parked overnight about 20 miles from the nearest paved road, 30 miles form the nearest phone, and about 200 miles from the only VW dealership in Alaska. I kept popping the plunger on the switch until I heard the relay click and then shifted into gear.

The glow plug caution light came on after the transmission locked in second gear after idling for 20 mins while in drive with the foot brake on. (My son and I were making bathroom runs/buying sandwhiches and sodas while my gf held her foot on the brake at the end of the parking lot.)

I did the reset logic circuit with the gas pedal thing and the trans worked fine. About 5 mins later I got the glow plug light. The manual did not say to shut down so I kept driving. It went away after restart.

Earlier this morning, I changed out the brake light switch. They're so easy to change and so cheap ($6.00) I bought two and put one in the trunk along with a spare T20 driver.

Thats pretty good that you totally diagnosed that with virtually no info.

I assume you put in the newest [non-GM] green switch? You shouldn't have to deal with that again.

oilhammer said:

I assume you put in the newest [non-GM] green switch? You shouldn't have to deal with that again.

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Yeah, the 1C0 instead of 1J0 part number, 4-pin connector. It had alreaady been replaced under recall, then again under warranty 3 months or so later. I got 60k miles out of the last one.

Yeah, the first recall was a different manufacturer, same design. The newest part is a totally different design. Luckily us B5 owners got in on the last design from the get-go.

oilhammer said:

Yeah, the first recall was a different manufacturer, same design. The newest part is a totally different design. Luckily us B5 owners got in on the last design from the get-go.

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Well, I probably did not need the second, spare part to carry around then. But, given the history, and considering that it will immobilize the car, fits in the glove box, and cost $6, I saw it as cheap insurance-if there is such a thing.

oilhammer said:

I assume you put in the newest [non-GM] green switch? You shouldn't have to deal with that again.

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WRONG! lol....

My girlfriend called, it failed about 3 days after I installed it lol. The car is in the garage and won't come out of park. I'm in Tampa for a family emergency and she won't try to replace it herself. She borrowed her dad's Excursion! Hooray for Volkswagen lol.

I want a copy of that "another one bites the dust" that you use for 01M transmissions so i can use it for brake light switches.

Lots of people install those wrong, that is why they had to put the instruction sheet in there.

I have never had nor seen one of the new design green ones fail.

oilhammer said:

Lots of people install those wrong, that is why they had to put the instruction sheet in there.

I have never had nor seen one of the new design green ones fail.

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I figured you'd suggest that I installed it wrong; I thought of it myself. I can't think of how I would have messed it up. Do you suggest reinstalling it or should I just toss it?

It will be another week before I'm home to deal with it.

Make sure the plug is seated first, and all 4 wires are secure in the connector shell. Then try wiggling the switch around and see if the interlock light goes out.

Like I said, I have never run across a bad new style switch, so I don't know what to think about it other than maybe get another one.

oilhammer said:

Luckily us B5 owners got in on the last design from the get-go.

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No we didn't. Mine has been replaced under the recall. The original did start acting up towards the end of my drive in the country last fall.

MOGolf said:

No we didn't. Mine has been replaced under the recall. The original did start acting up towards the end of my drive in the country last fall.

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No, I meant the first recall. The A4 cars had TWO recalls...the first just put a different brand (but same design) switch in. The second recall got the new design. The B5's only recall went straight to the new design.

I just replaced mine before our trip to Death's Waiting Room, but it had never given me any issues.

oilhammer said:

No, I meant the first recall. The A4 cars had TWO recalls...the first just put a different brand (but same design) switch in. The second recall got the new design. The B5's only recall went straight to the new design.

I just replaced mine before our trip to Death's Waiting Room, but it had never given me any issues.

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Yeah this is like the 4th one, soon to be 5th, for mine. So I got the 1st recall, which failed, the second recall, which failed and was replaced under dealer warranty, and the one I installed recedntly, whcih is...failed...or something.

Interesting to note, all the ones that did fail, did so within a week or so. This recent one went a few years.

Just be thankful you don't have an RX300...those came in for their brake light switch recall, and often left with a failed brake booster!

Boosters got recalled later, but our dealer had about a dozen stranded RX300s at the dealership for over a month. 'Passionate Pursuit of Perfection' indeed.

So, I'm back in Anchorage and got a chance to check this out for myself this morning. I can't make it fail. I did notice that there is a little play clockwise & counter clockwise as well as forward and back in the switch but ater 10 mins of wiggling in every direction, I couldn't get it to fail. Same with pulling on the wire harness and clip. So I'm done with it. I left the switch in and still have the back up spare in the car if a problem surfaces.

On a side note, while clearing out my voicemail, I realized that my gf's original complaint was that she could not get hte keyswitch to turn over. I asked her about it and now she can't remember. So I'm very done with this episode. =) Thanks for your advice, Oilhammer and others.