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I have a P29 (board 1720) that has a weird problem. With ignition key on, injectors click and remain open, fuel pump keeps running, solid CEL and no reaction to shorting those two pins on that blue connector. It's not even like limp mode. Something really weird. Replaced all capacitors and no results. Replaced the M82C55A-2 and no results. Replaced injector transistors and no results. Chipped it and burned the stock ROM and no results...
Has anyone experienced anithing like this? Who can help?

OK, I replaced the crystal and tested, it didn't work.
Then I replaced IC7 (M7U016-005), IC17 (TA8903SN) and those 2 capactiros around it, then i tested and... BOOOM! Now it primes the fuel pump and injectors are not stuck open anymore. But it doesn't turn the engine on. Seems like limp mode but i dont know why it can't turn it on. Maybe the engine has encountered a problem dou to previous tests with the faulty ECU.
Now I want to unchip it and test it again. I will post my findings. And still any experiences and advises are appreciated.

I removed J1 and 74HC373 and tested again. Unfortunately it did'nt work
Now i think that IC1 (OKI M66207 with 224 rom) would be the problem. How can i test it?

Update:
ECU is a P29 with 1720 board as you know it. IC1 OKI M66207 is bad for sure. I removed it and soldered it on another ECU and it failed. Tested the healthy M66207 on this ECU and it worked. Now I need to replace the M66207 but I don't have any of these ICs. ECUs with this ICs are very rare and expensive here. So I'm thinking about replacing OKI M66911 which I guss it has the same pinout with M66207 but with more RAM and no internal ROM. So it could work on a chipped ECU which has M66207. I'm not sure about this and I dont want to risk. So I need your knowlage about M66911 or it's datasheet if you have. Please help me in this. Thank you.

Thank you but there is no document about M66911 in this page and I already have M66207 datasheet.

Am I the first person who looks for M66911 datasheet? It's weird that there is nothing about this MCU.

I soldered a M66911 on the board and chipped the ECU and tested. It didn't work. EEPROM was tested on another ECU and it was fine. Chipping should be done correctly as I did the same process with same parts on another ECU and it worked.
I won't try to repair this ECU anymore unless I could source a M66207 MCU or I could find new information, specially the M66911 datasheet which I really want to have it.