Hi folks,
I have on the bench a MEMS3 ECU (MC68336/AM29F200BT) with absolute minimum connections 3x12V and 3xGND with one K-line. It is connected (via OBD) to a self-built circuit based on a (Canadian chip)323....not sure exactly what terms I'm allowed to use here. Just using Hyperterminal/TeraTerm or Putty I can get an ID from my circuit to 3 different computers using different OSs (XP, W10Pro/64 and W10home/64). I can then use an OBD command and get a Hex response from the ECU.....minimal because there are no sensors/actuators attached.
I am aware of seed/key and am not clever enough to generate programming to search for the map. I have done a basic ECU course at a UK academy and will probably have to do a more in-depth one next year. Can anyone give me a pointer as to books/articles I should read to gain more insight?
I'm 69, ex-airline pilot......not stupid (some say) and built my first computer in 1981. Happy with board level electronics....not smart at programming.
Many thanks.
Martyn

I probably should have added that this ECU is out of a club race saloon, not roadgoing. I also used an Italian OBD read/flash OBD unit to see if it would talk to the ECU CPU. Instead of a readable ID of any sort, I received 000000 on one line and 00 00 0000 on the next. When trying an ECU read, I ended up with an Errore SK: -1 message (Error seed key). Which is what prompted me to come to those who probably know. I cannot confirm whether the ECU has been previously 'race re-mapped'.
Martyn

Hi Martyn,

what exactly are you aiming to achieve? It's not really an ecu I use much (though I've a couple sat here, in addition a siemens unit for the kv6). If you've got the ecu to respond on bench though, read/write should also be possible.

The seed/key is just an authentication system for certain ecu functions, so depending on what your aims are or what equipment you are using it might be a moot topic.

Hi Dakta, Thanks for the response. It' a small club race team. I'm trying to understand the philosophy and operation of ECUs in general but this one in particular. I'm of an age where I was happy with spanners, screwdrivers and gauges. I wish to drag myself into an understanding (?) of modern car control. We are on a very limited budget and the ECUs for the championship are 'inviolable'. This is a spare ECU and a very theoretical exercise in understanding the basics in sensor/data reading and how the map/s are accessed and tuned. There are obviously fairly expensive bits of equipment that will do the job....but a/ it's not my money and b/ as you say, it's not a well known ECU/protocol. I've used an ***323 chip to 'talk' to the 68336 using basic OBD commands and I can get it to give me the VIN. I need to know how to 'transit' the 68336 and dump or read the AM29F200BT for the map. I have a book on MC68000 family assembly language....but my brain aches just thinking about it. All the best, Martyn