Bosie

Hello, I'm new to this forum thing and hoping someone can help me. My 02 TT Quattro won't move fuel. I replaced relay and fuse #28 (fuel pump) is fine. So I set out to replace the fuel pump. Once I got to the pump I test lighted it to make sure I had voltage to the pump, none detected. After a bit more research I discovered the fuse #37 (engine timing: petrol) was blown. Each time I replace it, it blows when ignition key is turned on (unless I remove relay before turning on ignition).

Some more back ground. I have owned the car for 9 months. I put all new coil packs and plugs in 6 months ago. Runs so much better. Recently a new battery. Has been a great daily driver until it stalled at a stop light last week and has not recovered.

Im completely stuck at this point. Any help you can be is greatly appreciated.

Thanks, Bosie

Mister Bally

Standard automotive electrical troubleshooting techniques apply. So, disconnect fuel pump from vehicle wiring harness. Does fuse still blow?

No; Replace fuel pump or something past what you disconnected.
Yes; Reconnect pump and disconnect the wiring harness at the next connection point.

Continue until the fuse no longer blows.

You will need a vehicle wiring diagram (read: proper service manual) and a good multimeter ( The free/$7.00 Harbor Freight ones are junk) along with some basic knowledge.

Bosie

Thank you Mister Bally for the good advice. That was the first thing I did was to disconnect fuel pump when I saw fuse was blown. It blew again with it disconnected. I did start to trace but didn't finish as you suggested because I had this nagging realization that its not the fuel pump fuse that is blowing out.

I think your advice to get a good manual is good, then I maybe able to determine what fuse #37 actually protects. Not sure which manual is a good one for Audi though

Also thanks for the advice on Harbor Freight. I have a Gardner Bender meter. Not much better but gets me there.

Mister Bally

Get the manual from Robert Bentley/ Bentley Publishers.

Bosie

Thanks again. I just ordered it. With slow boat shipping :O( I'll keep you all posted.

Bosie

Well it's been awhile since I worked on this Audi and made a post. I determined that fuse #37 is directly connected to the ECU power supply relay. I now have a new relay and fuse #37 is not blowing. The car still does not start. I have determined the following: the timing belt is good, the car does not have spark and it is not getting fuel. It only turns over. The code I am getting at the moment is P0685. This code reports "ECU Power Supply Relay open" not sure why I am still getting this failure when I have a new relay.

Any ideas.

Thanks

davecc

Hey, sorry for reviving an old thread but I'm having a similar issue, did you ever find out what was the problem?

Bosie

We'll I did get the car running. I think I had multiple problems. 1. I had an electrical short that was intermittently blowing fuze 37. #2. I also think my fuel pump was a problem because shorly after I fixed the short (fuze 37), the fuel pump totally stopped working and I had to replace it.the short was in one of the four sets of wires going to the coil packs on the spark plugs. Once that was fixed. It started. Good luck.

davecc

Thank you, will take a look at those!

Ralph Flores

Dave - did you get the car started? Did you replace the fuel filter by chance? Mine won't start, just cranks.