99 S4 Cutting out when stationary

[Jason182]

Had this problem for sometime now but it is now becoming very regular. When sitting in traffic or generally stationary for a while my car cuts out, when i try to restart it, it will turnover but not fire. After sitting for a while, it fires up again. It has happened 5 times over the weekend now and im pretty sick of pushing my car off the road as its damn heavy!!

Any ideas? My thoughts are towards the fuel system?

[Jason182]

Fuel pump relay changed today and made no difference! Still not any closer to solving this mystery,

[Dracoro]

I would guess at something along the lines of idle control, map/maf sensor etc.

TT will hopefully tell you.

It should register something in the computers I would have thought, get a local mechanic to take a look.

[Tame Technician]

As with any engine management problem you need to read the fault memory. There are probably 15 to 20 different things that could cause that so just matching up the symtom, as you have found with the fuel pump relay, will just have you changing good components.

My guess would be crank sensor, when they fail it they often start to work once they have cooled down, very few components fail in that way, but in tank fuel pumps can do the same. As I said, pointless to relace anything before you read the codes.

• If you want to do a bit of investigation before it goes to a garage.*

When its in a failed state see if you have fuel pressure, that will rule out the pump/relay6 wiring to pump etc.

When in a failed state check if you have a spark. (could be Crank sensot if you dont)

Also does the rev counter read while cranking normally (just before the engine starts), showing say 250rpm, if it shows something when it starts, and nothing when the car fails, is looking more and more like a crank sensor.

[EmmaP]

I had a problem with my car cutting out whilst running and also sat in traffic. I could not always get it to restart though. I had the crank sensor replaced but still the problem continued. When I had the ECU relay trip switch (I think that that is what it was called, it is a £10 part and is effectively the brain, at least that is what I was told) replaced the problem was cured. It might be worth getting that replaced first as it is a fraction of the cost of a crank sensor.

[Jason182]

Thank you for the replies. I have ran vag-com on my car and theres not a code to be found, i believe the crank sensor would throw one up? The RAC have also ran 2 diagnostics on the car and found absolutely nothing wrong but did notice that when cranking there is no fuel pump sound and the battery light flickers too?

Another suggestion i have had is ignition amps which is what i am going to check today by checking the temperatures of them when the engine cuts out to see if they are operating equally.

When the car cuts out, its as if it has run out of fuel hence why i always thought it was fuel related, but as it goes on and seems to get more frequent i truly am stumped on this one, but im forever the optomist!!

[Jason182]

Car has been a nightmare today, twice it has cut out at the most inappropriate times. When i eventually go it home i ran my laptop on it and it came up with these codes. Many havent showed as i have the shareware vagcom.

Thursday, 24 December 2009, 16:49:32

VAG-COM Version: Release 409.1-S



Control Module Part Number: 8D0 907 551 C

Component and/or Version: 2.7l V6/5VT 0002

Software Coding: 05611

Work Shop Code: WSC 00000

12 Faults Found:

17645 - Fuel Injector for Cylinder 1 (N30): Open Circuit

P1237 - 35-10 - - - Intermittent

17648 - Shareware Version. To Decode all DTCs

P1240 - 35-10 - Please Register/Activate - Intermittent

17647 - Shareware Version. To Decode all DTCs

P1239 - 35-10 - Please Register/Activate - Intermittent

17650 - Fuel Injector for Cylinder 6 (N84): Open Circuit

P1242 - 35-10 - - - Intermittent

17833 - Shareware Version. To Decode all DTCs

P1425 - 35-10 - Please Register/Activate - Intermittent

17938 - Shareware Version. To Decode all DTCs

P1530 - 35-10 - Please Register/Activate - Intermittent

17649 - Fuel Injector for Cylinder 5 (N83): Open Circuit

P1241 - 35-10 - - - Intermittent

17955 - Shareware Version. To Decode all DTCs

P1547 - 35-10 - Please Register/Activate - Intermittent

17646 - Shareware Version. To Decode all DTCs

P1238 - 35-10 - Please Register/Activate - Intermittent

17697 - Boost Pressure Control Valve (N249): Short to Ground

P1289 - 35-10 - - - Intermittent

16706 - Shareware Version. To Decode all DTCs

P0322 - 35-10 - Please Register/Activate - Intermittent

17963 - Shareware Version. To Decode all DTCs

P1555 - 35-10 - Please Register/Activate - Intermittent

[Tame Technician]

There is no way all those injectors and the boost solonoid + the unknown ones, are commponents failing, you just dont get that many components fail all at once.

Did you unplug the injectors or anything??

When an ECU reports most of the things connected to it as faulty, it either a faulty ECU or a major problem with the connector.

Can you locate the enginr ECU and make sure the connectors aren't full of water etc.

Can you clear the code with your version of VAGCOM and see which ones come back.


Try googling the numbers for a explanation of what the unknown ones are.

[Jason182]

The unknown codes come back as the rest of the cylinders plus charge pressure exceeded. It just doesnt make sense, since this i have cleared the codes and been out for a blast and no codes came on. I couldnt even get the car to stall as per usual!

It seems to me, not knowing that much, that there must be a grounding problem. There has to be a short in the car someplace that is just messing with the electrics? The garage that fitted my new turbos want the car back, so they must know that there is an issue someplace, unfortunatley the time of year doesnt help!!