mysterytrain

I have a 98.5 A4 2.8 tiptronic quattro that has become a bit of a problem lately. We had the car in for service in mid-june to reset the airbag light and to have the coolant temperature sensor replaced. A week later the car failed to crank after it was hot. The dealer [Princeton Audi] then replaced the ignition switch and of course the problem persisted. The dealer then cleaned the connectors in the console which i felt was told BS and again the car failed to crank after it was running for 30 mins or so. I was able to throw a VOM on the battery when the car was in 'no crank' mode and noticed that there was no voltage drop when I attempted to start the car. I ruled out the starter because of this. Looking at a schematic for the starter circuit I noticed the PNP relay and asked the dealer to replace it. Of course, they decided differently and said they where sure it was the starter because they tapped it and the car fired up. SO after 10 days at the dealership I get the car back and I'm assured that it was indeed a bad starter. I drive the car 30 mins on Saturday [ hot as hell in NJ ] and of course the car fails to start! Any thoughts on this before I break out the baseball bat? A bit more info for you. Car always starts in the morning. Car will always start if it sits all day at work. At this point new starter and ignition switch. I noticed that the coil on the PNP relay gets power from the ignition switch and it appears to get its ground connection from the the alarm. At this point I don't think its the alarm because we have not been locking the car and the condition persists. I'm not sure where the Park/neutral position relay lives..I'm guess in the console. During the no crank mode there is clicking from that area. Thanks in advance.
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Kris Hansen

but that does sound like the problem. Say, when you get this no-start situation, does the little light indicating to depress teh brake light up? Or can you just switch between D and N with no brake? I'd think if there was something wrong with the selector mechanism, you'd see odd behaivor with the selector/brake interface too..

mysterytrain

Nope, Everything on the dash looks normal. I can't shift unless the brake pedal is depressed [ so am i at this point]. I've tried re-selecting the gears. The big question i have is the PNP relay coil connection that goes back to the alarm unit.

Kris Hansen

When it starts up normally, you don't get that little clicking relay sound? You might rig up some sort of jump cable to the starter, and hit it when the car refuses to energize teh starter teh normal way...

Joey T

SUBJECT!

AudiDreamr

Stop going to that dealer.... they are just throwing parts at the problem. Is it at all possible that during driving the shifter or switch vibrates just far enough so that it looks like it's in park but the switch doesn't register it? Any DTC codes? I would look in areas they were likely messing with (such as the relay panel) because maybe they knocked a relay *just loose enough* so one pin isn't making contact. I read that you have not been locking the car. Does using the remote to unlock the car (even though it's not locked in the first place) allow it to start while hot? Also, I would try re-coding the key. That's the easy and simple stuff that I would do. Also, you sound like you have a good handle on how to troubleshoot these problems. Why don't you just DIY? it will save you a lot of money (especially considering the dealer you've been frequenting!)

mysterytrain

I can't imagine that this car is the first to experience this type of failure. I've done some searching on this board and I have seen that others have had the problem, but unfortunately, follow up posts are very rare and the solution is never posted. Diving into this is an option of course but the car has been towed twice when my wife [her car] was stranded to the dealership to have the car fixed in hopes that they would have the ability to find and repair the car quickly. I've been thru the locking and unlocking scenerio and the condition persists in both cases I have also ruled out the shifter positioning.

AudiDreamr

You're right about this car not being the first to experience this type of failure- I KNOW that i've heard of this before... As ridiculous as it sounds, you may want to expand your searching to include the 90 forum. It's been a while since I've been there, but if Mike Tip is still posting, he may have some insight from some older engines (the engines have changed over the years, but the design/mentality has not!)

How about a valet key (if your normal key has a chip/immobilizer perhaps something's going on there)
You could also try grounding the pin on that PNP relay with a jumper wire to allow you to rule out any sort of alarm system interference.

mysterytrain

Yeah, that was my next move the ground the relay coil. Funny thing is the dealer insists that there is no immobilizer circuit on my car. The key is the 2 button switchblade..but the schematic clearly shows a connection to the alarm. To me it looks like the alarm defeats the ignition until you trigger the remote or use the key. Now if I was the service dept I would have replaced [as I have requested]the PNP relay and given me back the car to drive. If it failed again then swap out the alarm box and see if that cures the problem I'm sure they have spares on the shelf! Yes, all keys give the same results.