# Digi II ECU Swap Compatibility



## CabiMatt (May 29, 2011)

Think I fried my ECU on my '90 Cabriolet (8v 2H motor). It's Digifant II P/N 037 906 022 BA. My question is what other 037 906 022 (xx) ECUs will work as a direct swap? I've found an 037 906 022 AT that is within driving distance. Will any of the 037 9060 22's work or am I setting myself up for disaster?


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## WaterWheels (Aug 14, 2005)

CabiMatt said:


> It's Digifant II P/N 037 906 022 BA. My question is what other 037 906 022 (xx) ECUs will work as a direct swap? I've found an 037 906 022 AT that is within driving distance. Will any of the 037 9060 22's work . . .


 Many of them will work and the list is rather long. The "AT" one you found will be just fine. Without trying to list all of the possible units that you can use, I will say to stay away from suffix "D" or "Dx" units as they will all be G60 ECU's I believe. The suffix in most cases just depotes a change which often has nothing to do with the operation. It is often components inside which were up-graded or sometimes programing to better work with one transmission or the other, things like that. I have seen some which for some reason the mounting was a little different, due to model space I guess, but they still worked if you just fabricated the mount to fit. Blah, Blah, the "AT" unit should work fine for you.


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## CabiMatt (May 29, 2011)

Thanks for the response. I fixed my broken 'BA' last night by resoldering a broken resistor that had corroded due to water damage. Temporary fix though until I find a replacement resistor so I can fix it properly or replacement ECU. I'm going to give the 'AT' a shot and if it doesn't work I'll just use it for parts to keep my 'BA' up and running. 5 band resistors are not easy to come by so it's worth $40 to me to have a donor ECU to pull from. 

As I posted in my other thread, my Cabby currenly has a 'BA' which I've found listed as a California code ECU. Every replacement I've found, including the 'AT', is a Fed code. That's my main concern as far as compatibility goes. I would exepct more significant differences between Cali and Fed than I would any other variation of the 'xx' suffix. 

ETKA only shows one currently produced Fed 2H ECU which is P/N '037 997 022 KX' remarks as superceding '037 906 022 EN' - that's a pretty significant change in part numbers going from a 906 to 997. I have no intention on paying $1000+ for a factory fresh ECU but the variation in the root part number is curious to me. This is the first VW I've built though so that may be the norm for them *shrugs* 

That being said, there are TWO current part numbers for the California 2H: 
The first is '037 997 022 LX' remarked as superceding '037 906 022 EP' 
The second is '037 997 023 X' remarked as superceding '037 906 023 AB' 

Some of the info here is for future searchers..


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## 1989Mulligan (Jan 26, 2017)

*Same ECU*

Hey there, I am having issues with my 1989 8v Golf flooding every time I hook up the coolant temp sensor. I suspect the ECU and I have the 037 906 022 BA model. Does anyone know if the 037 906 022 CT will work as a replacement? sorry to tack onto such an old thread.


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## Fat Rabbit (Nov 18, 2001)

Flooding is an indication of a fried ECU. In an abundance of caution I'd encourage you to also do some investigation -- check the grounds that attach to the coolant flange at the transmission end of the cylinder head and check (using an LED Test light) the injector pulse. Without a strong ground there the ECUs will fry. I'd check (or replace) the CTS itself and also check the continuity of the wiring back to the ECU Connector. A good manual will help with those tests. You don't want to fry another ECU. Over the years I have always tried to match suffixes on the ECUs for a "perfect" exchange. However when a match is not available the various suffixes on Digifant II ECUs do seem to be interchangeable. FR


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## garryt (Dec 22, 2016)

not sure about the differences in all the later ecu's. but I know the earlier triumph adler one was matched to 189cc injectors and the later bosch unit was matched to 214cc injectors. so maybe adding the earlier one to the later model would increase fueling??? rumour has that the digis run a bit lean at high rpms anyway. not my words though!:thumbup:


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## 1989Mulligan (Jan 26, 2017)

Fat Rabbit said:


> Flooding is an indication of a fried ECU. In an abundance of caution I'd encourage you to also do some investigation -- check the grounds that attach to the coolant flange at the transmission end of the cylinder head and check (using an LED Test light) the injector pulse. Without a strong ground there the ECUs will fry. I'd check (or replace) the CTS itself and also check the continuity of the wiring back to the ECU Connector. A good manual will help with those tests. You don't want to fry another ECU. Over the years I have always tried to match suffixes on the ECUs for a "perfect" exchange. However when a match is not available the various suffixes on Digifant II ECUs do seem to be interchangeable. FR


Thanks, I have already cleaned up all the grounds and replaced the CTS with an OEM replacement. I will work on the injector pulse and continuity and then see about finding another ECU.


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