ECU swapping / Immo3 codes and part numbers

[skott101]

Hi. Newbie to the forum so be nice!

I'm currently trying to get an Ibiza Mk4 TDI working that has had it's ECU stolen. After spending lots of time sorting out part numbers for the missing module and getting fobbed off by most dealers, i've finally been able to shed some light onto how the whole system works.

The immo3 system is split into 2 pieces. Half in the ECU and half in the instument cluster. When a key is inserted into the ignition the transponder code is referenced against the info stored in the ECU and cluster. If the code doesn't match in both units the code is rolled onto the next one ready for when the key is next inserted.

OK, the next sticky issue is the VAG part numbers. Normally 3 banks of 3 numbers and a lettered suffix at the end of the code. The 3 banks of 3 numbers are the hardware number, the lettered suffix are the version and immo3 code type.

While it's possible to substitute one ECU with the same hardware number and the wrong suffix at the end, it will never actually run as is. The reason for this is the rolling immo3 code. When the key is inserted and the code is wrong, both the ECU and cluster roll onto the next code, but as the cluster and the ECU are programmed to different codes and rolling code order, they will never pair up.

The only way round this is to change both the cluster and ECU as a pair. This way although the version number of the software is different to the original from the car, the immo3 code will match and then using either VAG.COM or a dealer you can recode the ECU to accept the immo code of the key you have.

Hope that helps anyone stuggling like i was/am!

 

[Uwe@Ross-Tech]

Actually, the ECU doesn't care about the key. Only the Immo itself (in the cluster) really cares about the key (and the rolling code in it). The ECU only cares whether it's has been matched to the cluster, and whether the cluster tells it: "It's OK to allow the engine to run". You can match a new (or used) ECU to an existing Immo/Cluster if you have the appropriate PIN/SKC codes using this procedure:

http://www.ross-tech.com/vag-com/cars/Immo3-ecu-swapping.html

-Uwe-

 

[tacroy]

I can help you with this problem, and I probably have an ecu that is correct for your car.
Please let me know the Ecu number you are looking for and I will have a look.

 

[skott101]

Thanks for the offer of help Tacroy.. i really need it!

Ok this is my situation at present. Bought a MK4 2004 Ibiza TDI with among other things wrong with it, the ECU was missing.
Contacted my local SEAT dealer who told me the ECU part number is :038 906 019 KT.

Sourced an ECU, Instument cluster and key from a salvage company from a 2005 TDI ibiza with the same engine code but a different end suffix on the part number.

Fitted it all into my car and despite the immo light & preheat lights flashing on the cluster, it does start for a second or so.

Tried to get a mobile company to come out to reprogram the ECU but had no luck. Having admitted failure i towed the car 20 miles to an obliging dealer (Premier Seat in Stoke on Trent). Despite claims of "yeah no problem, just get it to us and we'll get it sorted" and after almost a week i get a phone call today from them.

Apparently they have mated the IC and ECU together but the immo is still keeping the car from starting despite everything matching up. They gave technical support a call and they suggested that its the wrong ECU and dash for that model of car and that i should source the right one. Apparently in late 2005 they change to a k-bus? and that this would be incompatible with the equipment on my car. The dealer was pretty honest and leveled that neither them or tech support really knew what was going on. Oh or it could be the barrel decoder which is apparently expensive and non-returnable.

So i have a car which won't start and the dealer is talking about £1500 for new off the shelf modules which "may" solve the problem.

If anyone can help me with this, i'm willing to pay for time and traveling expenses if you can do what the dealers can't! Would be prepared to lose the immo on the car if bypassing it was the option to a running car!

 

[tacroy]

i have a KT ecu.
we can solve your problem 2 ways, i can turn the transponder off on any edc15, or i can recode my ecu into your car so you keep some sort of security with your car.
i don't mind which option you choose.

 

[skott101]

For the first time in a week, you've actually made me smile when i think of the car!

That's great news about having the right ECU. Ultimately i don't care which option we take as long as we can get the car running. It would be nice to retain the immo function on the car, but let's just do what's easiest for you. I really appreciate your help!

I'm picking the car up from the dealer today as he's exhausted all his options.

Would it be easier for me to send the electronics to you, or do you need to see the car to do the work?

 

[tacroy]

I spend alot of time in Manchester. I think its best if I come to you.
I will be in Manchester later today.
Try me on 07814328880
I will have the ecu with me.