EVERYBODY, need advice, Strangest TDI Problem yet

[wyseguy]

OK, first off, some background on this problem. As most of you know I had a 90hp ALH in my car to start with, then I blew it up, so I installed a 110 euro motor. This engine has been running for 15000 miles without a hitch using a ALH ECU with an upsolute chip for the most part. Several weeks ago, the car started acting up. I would start the car and it would die right away. No errors or check engine lights. It repeated this four or five times and then finally started. While driving down the road, the glow plug light started to flash, and the check engine light came on steady. I made it home and scanned the codes. Well 1 out of ten time I was able to communicate with the ECU (engine). I was able to bring up the airbag, brakes, instrument, and central convienance. WEIRD... So I finally get into the engine computer and find this DTC..

01039 - ECT Sensor (G2) Open or short to B+ - Intermittent
00562 - Fuel Consumption Indicator (Y10) Open or short to B+ - Intermittent

I clear those codes and go into the central convienance

I find... 01131 - Front Infrared Sensor (G166) Unknown Switch condition. This sounds like a sensor for the full alarm not even compatible with this central locking module.

So I'm confused. Now the car is acting up more than ever. I start it, drive 10 miles, shut it off and it won't restart. I decide to leave for the weekend and come to the conclusion this might be a Relay 109 problem, as the one I have was black and was extremely hot to the touch. I opened the case on it and the metal was discolored and smelled burnt. I called the dealers in grand rapids and lansing, as I was traveling down in that area, nothing till monday was the result.

On my trip (making sure not to shut off the car) I noticed much lag and turbo surge. Holding the accel pedal at the same spot caused lurches in acceleration, up to 80 down to 70, then the power would come back and I was at 80 again. Seemed like a boost valve was sticking or something. (BTW.. still haven't replaced a MAF sensor after 90000 miles on the car)

I call GEWILLI, stop by his place as he had a spare relay 109. I shut off the car, install the relay, and the car STILL won't start again. At this point, I'm extremely pissed with this stupid car, and geoff starts calling people for advice. We try talking to the ECU with my laptop and his, with both vwtool and vagcom, and absolutely NOTHING. We can't find out what the DTC's are stored inside. So now I'm stranded in lansing, with no running car. We mess with all sorts of [censored], unplugging batteries, reconnecting the plugs at the ECU, trying to start with a jumpered fuel solenoid, unhooking the coolant temp sensor... blah blah. Then for some reason the car started after it was all back together.

I'm on my way again, off to Toledo. I park the car at the hotel, shut it off, and try to restart.. NOTHING. Its dead again. I come back in two hours, it starts first try. I still cannot talk to it with vagcom at this point. I go to bed, wake up in the AM, go to the car, and it starts first try.

Now, it is extremely slow, and can barely make it to 70MPH on the freeway. I go to my friends house in ferndale (detroit) and stop the car. It doesn't start again. So I figure while I wait for it to cool down, I'll switch the EGR valve which is not in use with the N75 Boost valve. I get it back together, and the car starts. Drive it down the street and I have NO power below 3500, thgen it hits harder than EVER before. It pulls to 5000RPM , and boost comes on at 3500, no less. Its a turboless dog below 3500. I go back to his house, shut it off, and ride his motorcycle around a bit. 30 minutes after shutting off the car, try to restart to leave and no dice. It takes 12 cranks to get it to run at more than an idle and then shutting off. I'm on my way once again.


Now I'm driving to Grand Rapids again to drop a friend off. We are flyiung down 96, I mean, the casr is running AWESOME at 70+ speeds. it pulls to redline in 5th faster than ever before. So, I still have to figure out low rpm boost, but I'll take care of that when I get home. The car does not surge anymore, and holds speed better than it has in a long time. Its running better in warmer weather than I ever remember.

I'm about 50 mles from home, when all of a sudden, NO POWER. I can't hold 55. I'm definetly running boostless at this point. Now I can't talk to the ECU to see whats going on, and I can't shut off the engine as it won't restart. Now what? I drive home the rest of the way crawling up hills at 15-30 mph, hitting 60mph on downhills, and coasting tothe next hill. Royal pain in the ass.

Make it home, let it idle, grab my homework and go to a friends house. 3 miles away, still no boost.
Get there, shut it off, and try to restart. It restarts and this time with boost, went for a spin, and it was still not pullin low, but hitting hard up top. go back to his house, stay an hour, leave, and the car restarts once more, same boost condition, hiugh up top, maybe 30 seconds to 60, then it pulls like a freight train. REVs have to be above 3500 for ANY power.

This morning, start it up, and it dies immediately, try again and it runs fine. Go to town, still have no low boost, and high topend boost. I switch the valves back around, egr -> N75, and hit the road. I go get lunch, come back home, and shut it off. Start it and it runs, so I grab vagcom, and it talks to the ECU for the first time in 3 days.
Codes that it finds are

17571 - Fuel temp sensor (G81) Implausible sensor

17664 - Coolant Circulation Valve (N214) - Open Circuit


Now the car has been sitting for 5 hours, and it still won't start. Also can't talk to it with vagcom anymore.


No point in dealing with the dealer, as they won't know anything more than I do on these codes... I know its long, but any info any of you guys can shed on this is appreciated so MUCH. Thanks

William

 

[wyseguy]

Oh yeah, when I scanned the ECU today, and it talked, I also got a Transmission control module inoperative code. It was in the Instrument cluster, but the Instrument cluster is not coded for an automatic. ....

 

[MOGolf]

Silly, basic question: Did you check the grounding points on the engine, under the battery and in the plenum?

 

[GoFaster]

I agree, this sounds suspiciously like either a grounding issue or a (lack of) power supply issue. Sometimes if you write down every sensor you've had a trouble code for, and pore through the wiring diagrams, you'll score and find the point at which all of those seemingly separate circuits join together. Sometimes not. Good luck, I hate troubleshooting electrical problems!

 

[Genesis]

Sounds like your ECM has a bad ground - the odds of all those sensors actually being out that you get is implausible, and a bad ground to the ECU will make it impossible to talk to it on the connector since the reference for communications is gone too.

I'd go looking for high resistance connections between things that SHOULD be at ground the ACTUAL ground.

 

[dzljet]

Yep, I agree too. This sounds like a ground problem, the intermittent thing is the kicker. It might not be something you messed with, could just be a ground somewhere has gotten corroded and is losing contact now and again.
Sounds like a job for a Fluk and a 12pack and bring a cooler full of patience. A friend and I just spent a week off and on chasing down a short on an A2. PITA!!!

Oh, just a thought, have you checked all the pins on ECU connection? Any loose or bent one's? What about the lock tabs, are they closed up good? I'm sure you checked, these are jsut areas I'd look first.

Good luck, be patient.

 

[GeWilli]

MOGolf,

great suggestion!!! Ground. . . .

I'd add that when it was attempted to start - it sounded great. Just like it was normal, normal injection sounds.

BUT it died. No-shut-off-valve on.

#1 sounds like you have a leaky vacuum somewhere Will. Grab a mity vac and test the vacuum points. I noticed the 6-4mm adapter stepdown that goes to the VNT was not connected real well could be leaking and causing your problems.

Next time you get the computer talking to the ECU don't turn the car off and drive around and log Data block 11.

Engine ground defiantely would make sense. So pull the battery out and remove the battery tray and start with that ground point. It might be corroded or not hooked up well. Then start running around looking for the rest.

Sooooo

You've got the two most fun trouble shooting: Electrical and Vacuum

good luck will (next time I'll call Glen - if I can find his number

)

 

[MOGolf]

I should also suggest ensuring good battery connection, and no loose fuses. If you get VAG-COM to talk to the ECM again, I would suggest going to basic setting mode and use the "reset to factory" function to clear anything that is awry. Then double check other adaptations that may have been done.

Also make sure nothing has mechanically slipped (e.g. belt tensioner).

Vacuum problems too? Well that sucks.

 

[wyseguy]

I did the vaccuum testing today actually, as I suspect my N75 to be going south. If its not one thing, its another.

I'll check ground points...good call. Why, though, am I not able to talk to the ECM? It would seem that if the car were running well, the ECM is working, yet I cannot communicate with it 95% of the time. It does seem, however, that when the car starts when hot, and right after being shut off, that vag-com talks to it. I'll know more tomarrow. I'm gonna pull the wiring harness out, and replace it with the one from the old engine, move the connector station back to where it belongs, and get a boost gauge installed to get info on that whole -- maybe unrelated situation -- is coming along.

Thanks again!!


BTW, more on vaccuum, I did go through it and test with the mityvac, but does anyone know where a vaccuum diagram is, as the bentley does not seem to have one that I can locate. Thanks

 

[MOGolf]

Vacuum diagram is at the end of the EGR system - section 26 in the e-copy (I don't have paper copy with me).

Other references to non-standard wiring harness now makes me think of possible loose connectors, or damaged (e.g. pinched, abraided) wiring.

 

[GeWilli]

its by the EGR stuff in the Paper book too.

it is also in the engine bay but the sticker probably still isnt on your car is it

 

[wyseguy]

maybe it is

didn't check that....

The wiring is fine. I'm suspecting a ground on the Kline is intermittant, hence the no talky to ecu

Its not the ECU itself. I'll keep you guys posted...

Thanks

 

[BGUERIN]

Im no expert bUT did you disconnect the battery B+ and place an ammeter in series and see what is being drawn with nothing on. I think the bentkey manual states a max of 125mamps. If it is the ECU just chck for a cold solder joint. Look foe any transitor on a heat sink the may have unsoldered. This is usually where you get cold solder joints
because the part tends to vibrate mote and become unsoldered.

 

[Little_Stinker]

I used to work in an auto electrical shop. Any electrical noise from the alternator or a stereo/amplifier? Have you unplugged, cleaned and tested every plug and grounding point? Do you have a spare ECU to try? Have you disconnected the battery and run resistance tests on the wiring from point to point on the ECU and engine harness? I realize that having this done at VW would bankrupt most folks. If your mileage is below 150,000 miles you can purchase an extended warranty from an independant company and wait a couple of weeks then take it to VW. You only pay a deductible then. Food for thought.

Good luck

 

[wyseguy]

no one else is ever going to play with my car but me, until I sell it. I have been to 5 VW dealers with this car in its prior life, and have never found anyone knowledgeable or competant. I have tried a spare ecu, and I have no noise through my stereo. I am changing the engine harness out right now to a different one I have.

 

[GeWilli]

there isn't a dealer in michigan that doesn't "know" this car - and I doubt he'd be able to get service on it warranty or not even with an extended policy

keep us updated Will!

 

[wyseguy]

Why thanks geoff

I would not even think of getting any warrenty. I've always stepped up to the plate. This damn car has costed me more than a new bimmer would, I swear....

 

[wyseguy]

Problem is resolved.. Well the car has been in the garage since the last post. Sitting on 4 jackstands, 3 feet in the air. After purchasing a third ECU, and borrowing a fellow TDI'ers 2000 Flash Red 4 Door Golf for testing purposes, I have finally gotten to the root of the problem. Throughout this, I pulled the entire dashboard, and checked all grounds. I went through every possible wire, or so I thought. Grounds seem to be the major assumption until a few days ago. I had already changed to a different harness on the engine side. The problem lied in the second 60pin ecu connector.. on the left. This bundle of wires contains signals for all sorts of important things, one being the Kline to the instrument cluster. The wiring from the instrument cluster to the orange connector in the white waterproof box under the rain tray ohmed out.. The kline wire 12 inches into the harness ohmed out. The ecu connector side also ohmed out 12 inches in. So the intermittant break, or corrosion (most likely) somehow is contained in a tightly OEM wrapped harness that is one of few things never disturbed by me. I jumpered it, as the car can't come out until saturday anyhow. I will repair the wire tomarrow and find out exactly what is going on. This was the ONLY problem when I was stuck in Geoffs driveway, or at any other time in my diagnosis. I even used a friends ECU and the car started... put my in and it wouldn't start. Put his in and it would start. So I ordered another one, to make three. It showed, and now it wouldn't work either. Took all three of my ECU's to a dealer and tested them, all are PERFECT. Back to the wiring I went. This problem was a ***** to find, and I even think I went about things damn methodically. The wire had enough continuity to beep on the fluke multimeter I was using. Unbeleiveable. New pics of the car with a few minor additions sometime this weekend. ITs back in summer mode, greater than ever minus the 100% STOCK interior I now have

.. How nice it will be to have MPH in my cluster again

later.

 

[GeWilli]

I was thinking about asking you if ya found the problem!

Too bad ya got the 2k golf or i'd buy one of those spare ECUs off ya

So we'll see you at Hondo's?

 

[wyseguy]

when is hondos?

 

[MrMetal]

when is hondos?

Saturday, May 24th, it looks like. Sign-up thread is here .

Feeling all productive and stuff,

Adam