URs4 engine trouble

[AUDIS2avant]

A friend of mine has a urs4 and am having trouble getting the engine started.
In vagcom it had no faultcodes, it gets gasoline but NO spark.
Only just a small amount when the ignition is turned on, but not when crancking.
He has changed, PAS modules, igniters, testet camsensor with a small lamp.
Checked the flywheel, all we havent testet is ecu and engine wire.

Any ideas?

[UrS4boy]

One AAN/ABY/ADU missing & hestitation diagnostic procedure

Suggest that you read through this. Might help.

http://forums.quattroworld.com/s4s6/msgs/22611.phtml

The other thing is whether the AAN in question has the proper ECU harness grounds to the back of the cam cover and the intake manifold. Without these grounds, the ECU via the POSs is unable to provide a ground pathway to create the necessary spark.

[AUDIS2avant]

I hoped you would answer.
Will check up again on the ground connectors, but he did make a temp cable to check it tho, but to no vail

[UrS4boy]

Another thought: If you are still running the OE coils and POSs, the AAN coil wiring can get brittle and crack and sometime short out between the cam cover and the "20V turbo" coil pack cover. When this happens it blows the S64 coil fuse/circuit breaker:


Photo courtesy of SJM Autotechnik

Short term solution is to wrap the broken wires with electrical tape and replace/reset the fuse/breaker. Long term solution is replace the coils or at least the coil wiring.

[UrS4boy]

...

[AUDIS2avant]

Super, thanx m8.
He also found out that the ecu is gone bad, så he has to change that also

[UrS4boy]

Super, thanx m8.
He also found out that the ecu is gone bad, så he has to change that also

Be careful. How does your mechanic know that the ECU has gone bad? Because one of the DTC codes says "J220 bad"? It might be true but I would just try another ECU in there before a decision is made to replace. ECUs are starting to go bad but it is still very rare and there are other reasons the engine has problems.

[AUDIS2avant]

He tried it in another car, it had automatic gear tho, but it dident start, så if the ecu´s are the same then it´s faulty

[Gormj]

Thanks for all the information, it is my URS4 that have a problem.

I tested my ECU in another URS4 (an automatic, mine is a manuel but as far as I have read it should not be a problem when testing the ignition), in the other URS4 my ECU did not work, no sparks on the plugs.

I have checked the S64 fuse and it is working (also measured 12volt on the 2 connectors on the coils).

My ECU have part number 4A0 907 551 AA, I can see it have been replaced by 4A0 997 551 X.

Does anybody knows if a URS6 ECU 4A0 907 551 C be used instead ?

[AUDIS2avant]

Hi gorm

[S2central.net]

Thanks for all the information, it is my URS4 that have a problem.

I tested my ECU in another URS4 (an automatic, mine is a manuel but as far as I have read it should not be a problem when testing the ignition), in the other URS4 my ECU did not work, no sparks on the plugs.

I have checked the S64 fuse and it is working (also measured 12volt on the 2 connectors on the coils).

My ECU have part number 4A0 907 551 AA, I can see it have been replaced by 4A0 997 551 X.

Does anybody knows if a URS6 ECU 4A0 907 551 C be used instead ?

I cannot remember if the 'C' on that part lines up for AAN with Automatic gearbox, or if it is an IMMO variety... If your car doesnt have key transponder then it will never start with an IMMO type ECU.

You need to determine if you have good signals at G4, G40 and G28 - dammit this comes up all the time - I need to make a sticky once and for all.

[UrS4boy]

I have checked the S64 fuse and it is working (also measured 12volt on the 2 connectors on the coils). My ECU have part number 4A0 907 551 AA, I can see it have been replaced by 4A0 997 551 X. Does anybody knows if a URS6 ECU 4A0 907 551 C be used instead ?

This might help:

[Gormj]

S2central.net> G40 and G28 sensors have been changed, G4 have been checked and is working.
The 'C' version is from the URS6 AAN with a manual gearbox.
I have had the ECU in another car and it did not work there, this is why I am 99.999% sure it is gone bad.
The injectors are working and there is no error in the memory of the ECU, a bit strange I know.

I might be able to get a 'C' version, I was hoping it might only be a small change for the better or another mapping in the 'C' version as the engine is the same (AAN, manual gearbox) but I just want to be sure I can use the 'C' version before buying one.

[prj]

I have had the ECU in another car and it did not work there, this is why I am 99.999% sure it is gone bad.

It didn't work there because your car has immo!!!
It will never work in a non-immo car without modification.

And if other car has immo, it will not work either! You can't swap IMMO ecu's between cars, it will not work.
You need to adapt the immo block to the ECU otherwise car will not start.

And if you get a new 551C ECU, it will not work on your car EITHER without adaptation, just like it didn't work on the other car.

But, I will gladly take the "broken" ecu off your hands.
Can I have it for only the shipping price?

[Gormj]

There is not IMMO in my car (have made my own flip key and there was no immo in the originle key) but i do not know about the one I tested it in, I will have to talk with the person that owns it.