dcdrechsel

I think there is an easy way to check Ignition switch and also dme .At the relay-pin 86 is Ignition switch with key on should be b+ ,pin 85 is dme which I think is the ground .With pigtails should be able to test both conditions ; voltage from ignition switch and is the dme completing the circuit .If the dme isn't completing the circuit -I am clueless
Dave

rkellison

Ignotion switch checks out ok. I think that the DME is toasted. All the systems are powered up and check out ok. Injectors, coils and fuel pump all have proper voltages. From what I cna gather, the DME gets signals from the AirBag module and the Alarm Module to allow engine start. If it does not get a all systems OK then it prevents spark, injector and fuel pump operation. That is what I have now. No codes and all systems have power but no DME signal to start working.

Has anyone replaced a DME? Can I get this one rebuilt?

logray

I have a PST2 and have re-flashed two DME's with it. It is somewhat a black art with the DME 5.2.2. Yours though is a 2001??? DME with Motronic 7.2.x?

Failing DMEs are rare though, I would actually start with the less expensive VW part ignition switch replacement before the DME, because the DME is expensive and can also be a pain to get flashed, programming codes retrieved and changed, etc.

If you can't reflash your DME, the EEPROM can be de-soldered to be re-flashed, however this is seriously geek stuff... basically micro processor repair. You would be better off to source a used DME with the codes and try to re-flash it with your car's immo, alarm, and dme codes.

rkellison

Mine is a 1999 ME5.2.2. There seem to be a few folks that rebuild these. It would be great if I could get my hands on a schematic for the unit.

rkellison

Can you pull the codes off the one that I have?

redridge

when you put the key in... does the window go down? It prob thinks its still in a crash... hence no spark and fuel.

logray

You could try a DME reflash. However I wouldn't trust a clone PIWIS to do it, I've read several horror stories about that. I have done it with a clone PST2. It is seriously black magic with the 5.2.2 and a clone PST2. If you have a genuine PST2 it is less "scary", but your chances of success on a DME reflash are greatly increased with the DME on a bench out of the car.

You can get the programming codes for your entire car from a dealer, just show them proof of ownership.

If you want to send your DME to the "pros", here they are: http://www.protomotive.com/home.html.

I agree with redridge, I still think your AB module is acting up, but you said earlier you unplugged it and the car runs?

What are the guys at Durametric saying? They are REALLY knowledgeable when it comes to DMEs. IN fact, probably the most knowledgeable.

You have some serious gremlins in there, I think the ignition switch is worth a try if you haven't attempted that, it's cheap, readily available at your VW/audi/porsche dealer and easy to do.

rkellison

The windows do not go down when I put the key in. The ignition switch checks out with the proper voltages in all positions. At first it ran without the AB unit plugged in. Now, nothing. No fuel pump, no injector signal and no spark signal.

dcdrechsel

I believe you said that the Durametric could activate the fuel pump .This would tend to suggest that the dme might be ok .What is vague is the airbag control unit .The documentation says that after three activations it's history .Don't know what logic they used in the unit but I would think that everytime the key is activated it's a cycle -Doubtful they log a fault and ignore that same fault on the next cycle .Durametric may know answer to that .
Dave

logray

Even though the ignition switch seems to check out electrically, it might still be bad, I've read a few threads similar to this on renntech. If you try to jiggle the key or move it a little up or down or left/right does it make any difference?

Other things to check are clutch switch, DME fuse, fuel pump relay.

I am still a non-believer when it comes to the AB module as well, I'm surprised the car even ran without it.

rkellison

Dave, I read airbag activation as a deployment. After 3 recorded instances it is time to replace it. I am getting an oscilloscope to check the signal at the Injector, crash detection and ignition coils. Maybe that will be the smoking gun that I am looking for.

Owen at Durametric said that the codes looked good. Nothing there that helps much. That is what pointed me to the DME. All the input signals are correct but the DME does not tell the engine to start.

dcdrechsel

I believe the car is a tiptronic-is there any special interlock on those ?Like a neutral safety switch ?

ltusler

Yep, these are to goto guys for DME reprogramming. My car is a bit of a frankenstein with a 99 chassis, a 2002 engine and the 5.2.2 DME. They can make CEL's go away and not come back.

Pac996

Have you tried having everything turned off and disconnecting the battery, then let it sit over night and try reconnecting the battery being certain everything is turned off ignition switch and all?

Maybe there is a continuity check you could do with the key out and battery disconnected. You've proably already done that though. Sure sounds like a pain trying to diagnose this problem.

One more thing. Do you have an sudio amplifier that might be holding power so that when your battery is disconnected the amps capacitors might keep power on the system instead of the bleed down resistor doing it's thing?

rkellison

Yep, tried all the easy stuff. The Tip has the standard "P" lock so you have to put it in Park to crank it up. I called today and talked with a DME specialist in FL. He gave me a couple of items to check. I did and the DME and Alarm modules are on the way to FL now. Hopefully, that will come up with something. In the mean time we are polishing and trying to decide on new clearcoat. The Pearl Black is in great shape but the clearcoat is a little dull with the 100K plus miles of nicks. I have to say that I did drive it down the street and back before it had a problem. Since it is a new rebuild, I was easy on it and did not floor it (althought I was tempted). I gave it "strong" throttle and it was like someone kicked me in the butt. Zero to 40 in 3 driveways. NOTE: (No pedestrians or small animals were injured in this childish act).