URs4 engine trouble

[prj]

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.

551C is an immo ECU.
So you have immo on your car.
And yes, there is immo in the original key, it's just a small bar.

It's possible that there is an immo emulator installed for the original immo by someone, but that still means that your ECU has immo and swapping will not work.

Is your ECU chipped or stock?

[S2central.net]

Hold on - I thought he said he tried a spare/other ECU that was 551C - hence IMMO. Maybe I am confused.

Easy way to tell if car has factory IMMO is whether you get the little 'car with key' lamp that lights up on the dashboard before starting. If it doesn't have that lamp then its a NON-IMMO and an unmodified 551C ECU will never start the engine.

[prj]

Hold on - I thought he said he tried a spare/other ECU that was 551C - hence IMMO. Maybe I am confused.

Easy way to tell if car has factory IMMO is whether you get the little 'car with key' lamp that lights up on the dashboard before starting. If it doesn't have that lamp then its a NON-IMMO and an unmodified 551C ECU will never start the engine.

His ECU is 551C, and he tried it on another car. If you take a 551C ecu and put it on any other car, then unmodified it will never work on the other car.
You'll either have to modify the ECU if the other car does not have immo or adapt the ECU to the immo block in that car.
That lamp can be broken as well - mine never lit up until I changed the bulb.

Anyway, all euro UrS6 have immo. So his car by definition has immo, and the immo ECU just further shows it.

You understood everything correctly. From what has been written until now - they are fitting an immo enabled ECU onto another car, then say it's broken because the other car does not start

[S2central.net]

But then why did he say he had a '551AA' that had been swapped to a '551X' at some point.

And from what I know - moving an IMMO ECU from one car to another IMMO car will not work either without some VAGCOM tricks and passcodes etc - or maybe that is just needed when coding keys - cant remember.

[prj]

But then why did he say he had a '551AA' that had been swapped to a '551X' at some point.

And from what I know - moving an IMMO ECU from one car to another IMMO car will not work either without some VAGCOM tricks and passcodes etc - or maybe that is just needed when coding keys - cant remember.

Oh, I see now.
But there is no "551X" ECU. Does not exist.

UrS4 does not have immo, I got a bit caught up on the 551C ECU so for some reason thought he has a UrS6.

Gormj:
Take a 551AA or 551B ecu, fit to your car, and see if it starts... You can take the ECU from the automatic.
But 551C, 551D, 551E, 551F ecu won't work on your car without modifications.

It might also be worth opening up the old ECU and looking, maybe someone has chipped it and done a bad soldering job.

[S2central.net]

From what I remember - a '551X' is what you get from Audi / Bosch when getting a new one as exchange item - no way to know what that is of course - whether immo or manual vs automatic.

Confusion reigns - if OBD talks to it then see what signature you get by way of part number as that will tell what software it is running - assuming it hasnt been messed around with.

[prj]

From what I remember - a '551X' is what you get from Audi / Bosch when getting a new one as exchange item - no way to know what that is of course - whether immo or manual vs automatic.

Confusion reigns - if OBD talks to it then see what signature you get by way of part number as that will tell what software it is running - assuming it hasnt been messed around with.

Yeah... does the ECU respond to OBD with ignition on?
That could bring some clarity.

[Gormj]

Just to clear things up a bit here.

My ECU is a 4A0 907 551 AA (manual), it is not chipped and have never been chipped.
I have tried in a car with a 4A0 907 551 A (Automatic).

I have tried to get a 'C' version.

I have been told that the "new" sparepart number from Audi is 4A0 997 551 X (I do not have this verision in my car)

Is it possible to change/remove the IMMO from a 'C' ECU, I have access to VAC-COM.

[Gormj]

When checking the ECU with VAG-COM I do not get any errors at all, even after running the car on the starter for 10 seconds.

[prj]

Is it possible to change/remove the IMMO from a 'C' ECU, I have access to VAC-COM.

Yes, it is possible, but not with vag-com...
I can help with that if need be.

But with VAG-COM, you have access to the ECU?
If you have access to it, it's very weird that it won't start or register faults.
Try accessing it via the menu -> Engine block, not just doing "auto scan".

Also, it's possible there is some short on your car that fried something in the ECU, and there is no guarantee that when you fit the new ECU, that the same won't happen...

If it responds to OBD, that means it's not getting signal from G4, G28 or G40.
You could try opening the ECU and looking at where the pins go and if something looks blatantly wrong on there.
When the car is stopped it should always have "Engine Speed Sensor" error. If the ECU does not see input from the Engine Speed Sensor, it will not start the car...

[Gormj]

Here is a quick overview of what happened

1) When driving in the car it started running on 4 cylinders (have tried this before, once it was a defective coil the other time it was a POC)
2) When trying to find what cylinder was not firing, I started to unplug one injector at a time, suddenly the engine just stopped.
3) Started the engine again, then it was running for 2-5 seconds before shutting down again, after a couple of tries to start the engine again it did not start at all anymore.
4) Found a defective coil (exploded), changed all 5 as I had a complete set I know is working, enginge still not starting.
5) Change both POC's and the 2 crankshaft sensor, still not working.
6) Have checked the camshaft sensor several times and it seems to be working (can see it breaks the signal for each turn of the camshaft)
7) There is power to the two 12volt connectors to the coils
8) There is no wiring breaks between ECU and POC's

Sometimes when turning the key the 2 position (not running the starter) it will make a spark on sparkplug 1, but it is not everytime it does it and sometimes (one of every 10-20 times) when running the starter I get some sparks on different plugs but only for a second and then it stoppes sparking.

[prj]

Check:
1) Connect with VAG-COM and check Group 000. Are you able to view the values?
2) Crankshaft position sensor - Pin 47 on Motronic
3) Engine speed sensor - Pin 49 on Motronic

If you are able to view the values in VAG-COM and all of the signals are there.
Open ECU, trace pin 49, inspect for damage.

If you are not able to connect with VAG-COM, but all the signals are there.
Open ECU, inspect all the grounds and +12V pins and see if there is a cold joint/damage.
Pinout here: http://www.s2central.net/motronic_pinout_ABY.html

If you are sure all signals are there and you can not or do not want to find the fault in the ECU, and want to use the 551C ecu, the ECU will need to be modified.
It's a soldering job on a 551C and you need appropriate software.
I can help with that if needed.

[Gormj]

Yes, it is possible, but not with vag-com...
I can help with that if need be.

But with VAG-COM, you have access to the ECU?
If you have access to it, it's very weird that it won't start or register faults.
Try accessing it via the menu -> Engine block, not just doing "auto scan".

Also, it's possible there is some short on your car that fried something in the ECU, and there is no guarantee that when you fit the new ECU, that the same won't happen...

If it responds to OBD, that means it's not getting signal from G4, G28 or G40.
You could try opening the ECU and looking at where the pins go and if something looks blatantly wrong on there.
When the car is stopped it should always have "Engine Speed Sensor" error. If the ECU does not see input from the Engine Speed Sensor, it will not start the car...

I have tried the Menu -> Engine Block.
I get the "Engine Speed Sensor G28" error as normal, sorry forgot to write it in the earlier post.
I get no errors on the other sensors.
Have tried to disconnect the other cranshaft sensor and I got an error for it in the ECU when it was not connected.

As you are writing I also suspects something fried the ignition part of the ECU, have already checked the ECU inside and have not been able to see anything wrong, no bad soldering, black areas....

Maybe the exploded coil have fried a POC and then it have fried the ignition part of the ECU.

[Gormj]

Check:
1) Connect with VAG-COM and check Group 000. Are you able to view the values?
2) Crankshaft position sensor - Pin 47 on Motronic
3) Engine speed sensor - Pin 49 on Motronic

If you are able to view the values in VAG-COM and all of the signals are there.
Open ECU, trace pin 49, inspect for damage.

If you are not able to connect with VAG-COM, but all the signals are there.
Open ECU, inspect all the grounds and +12V pins and see if there is a cold joint/damage.
Pinout here: http://www.s2central.net/motronic_pinout_ABY.html

If you are sure all signals are there and you can not or do not want to find the fault in the ECU, and want to use the 551C ecu, the ECU will need to be modified.
It's a soldering job on a 551C and you need appropriate software.
I can help with that if needed.

I will try this, thank you

[prj]

I have tried the Menu -> Engine Block.
I get the "Engine Speed Sensor G28" error as normal.
I get no errors on the other sensors.
Have tried to disconnect the other cranshaft sensor and I got an error for it in the ECU when it was not connected.

Ok, but have you checked G28 with a scope?
Is there fuel but no spark?
Have you tried if the car starts when towing it in gear?

As you are writing I also suspects something fried the ignition part of the ECU, have already checked the ECU inside and have not been able to see anything wrong, no bad soldering, black areas....

Maybe the exploded coil have fried a POC and then it have fried the ignition part of the ECU.

Could be, but the likelyhood is very low, that's why it's better to check everything else first.

Is it possible for you to take an ECU from another car temporarily (551A/551AA/551B) and try if your car starts with that ECU?
If it does, then you will indeed need to replace the ECU, but as I said before, 551C will not work without modification.