AAN ECU 1111 fault code problem.

[rs200]

hello.
well I bought one AAN ECU (automatic gearbox) car was in mint condition if we look tehnical parts, evrithing was fine.
I put them in my car and find out that "check" light is always on. than I go get fault code it was 1111. after that I went to run the car and check light gone. until next start of engine. same procedure again.
car run perfect.
than I take the ECU out and put tuned chips in it. everithing is the same. I try this ECU on friends S6, and there is same problem
ECU have X on cover , and it mean that it have bridges for chips, they are not welded.
my old ECU don't have those bridges, but my electrical put them in , so now I can change chips .
can that make any difference?
can I fix somehow this check light?

[rs200]

this is copy / paste simptoms from SJM..

1111 (Blink Fault Code), 65535 VAG1551/2 Fault Code Number
Engine Control Unit (ECU) Defective memory circuits,
Incorrect Checksum for internal memory (EPROMs)
(this can occur on some modified ECU's) Check ECU ground connections, Check EPROM programming
Symptom: Check engine light may come on

we clean every contact again , and there is still light on.
same problem on stock and tuned chips.
engine run perfect.
what can I do to fix that?

[UrS4boy]

As an autobox AAN, it might be lonely for its former companion, the Autobox ECU. Look at the Pin T55/51 and T55/54 info in this AAN ECU post. Also post a photo of the ECU showing the "X". "X" at the end of a Part Number often means rebuilt.

http://forums.quattroworld.com/s4s6/msgs/21009.phtml

[rs200]

here I have one ECU it is not exactly this ECU what we talking about. because right one ECU stays in friend's car to check what will happened in next few days. will ECU still run OK.
but here is picture of "X" ECU , what means that chips are not welded , they have socked for chips. plug n play.
picture of ECU which is in your link don't have it, chips are welded on board.



can you see the "X" which is pressed in metal cover? that is "X" what I'm talking about

[rs200]

is there any code for vag com , that we can make it to forget the automatic gbox?

[UrS4boy]

can you see the "X" which is pressed in metal cover? that is "X" what I'm talking about

The one in the photo definitely is the wrong ECU. 447907404A was the 3B ECU but is was superceded to 447907404AA on 30/11/1990.

I see the "X". The very early AAN ECUs, to maybe as late as Feb. 1992, had socketed chip sets from the factory. I had never associated the presence of the big metal "X" with the factory-socketed chip sets until now. Based on the 447907404A ECU in your photo, I am guessing that they (Bosch) where mostly just using up old cases.

[UrS4boy]

is there any code for vag com , that we can make it to forget the automatic gbox?

"51/55- Not used for standard transmission cars - relates to kick-down shift point for automatic trans cars. Third digit in VAG-com measuring block 005. Normally "0" until kick-down with Autotrans when it goes to "1". (Thanks to "MG" on the S2 forum for this info)"

My guess is somebody like prj could fix the 005 measuring block to say it is a manual transmission.

[rs200]

I will take a photo of this ECU and you will see that they have X on it , car is from 93. and I was a first person who open the box of ECU to take them out , because the carpet was still in one piece , and have to cut it with knife on the top , maybe 10cm , near that carpet is already cut.
I read somewere on net about that X marks on AAN ECU , and they are true . confirm that several times . maybe it was the early version, but who cares .. don't have to open it to find out did they have socked for chips or not ..

I will talk about that reprograming the ECU with my electrical. maybe he can do it.
hope that this is my problem. when I fix that (if I) , will post here , what have to do if somebody will have same problem in future

[Angus Young]

yup, If anybody has any more suggestions ure more than welcome 2 share it with us!
Car runs great on that ecu but it doesnt wanna show any errors only that 1111 fault code.
I was wondering was it safe to drive like that but car shows no problems and runs ok. What do u guys think? So hope we find the way to reprogram it... Please, help

[prj]

That X means absolutely nothing. Just old cases.
The chips in the ECU need to be rewritten most likely, and that's about it.

[Angus Young]

Thank you for answer but we replaced the chip with the tuned one and it still shows the fault code...

[prj]

Thank you for answer but we replaced the chip with the tuned one and it still shows the fault code...

The chip? There are two chips. Did you replace both? Did you clear the code afterwards?

[rs200]

of course we change both chips. and we clear the codes few time.
there are always 1111 code. nothing else. actualy I want to say if we disconect some other sensor, ECU don't show them. only 1111.
strange but true !

[prj]

65535 means incorrect checksum in one of the chips, nothing else, nothing more.
It is calculated by adding all bytes in the rom, and comparing them with a stored sum.

If it is incorrectly reading the chip in some parts, it can be a number of components that are going wrong...
Have you considered the fact that both chipsets might be damaged? or is the other chipset OK in the other ecu?

[rs200]

even the stock chips which are OEM inside the ECU are wrong than. they show fault code 1111 too.
I was the first person who open ECU. we try to put in my car , friends car , and in both cases there are this fault code. than we try with tuned chips and there are no difference . same code , same problem in both cars.
this ECU is only ok in his stock OEM car. everithing is fine there.
very strange !