ECU Swap and Check Engine Light flashes

[zandi]

I replaced my 380 ECU with a 173 ECU and now my engine light flashes frantically when the car is on, can anyone tell me why?

[zandi]

More: My car is a 1989 325i 5spd, and I think the 173 ECU is from a 88 525i. Someone help!

[Kruzen]

hit the check engine button?

[mentaleeill]

is it the check light or the engine light flashing? the check light is just to get your attention to look at the overhead panel, that a light is out or something. if thats the case just hit the check button on the panel.

[zandi]

The ENGINE LIGHT is flashing...not the check light

[zandi]

So I installed a 526 ECU and the 380 ECU again and it works no problem, but the 173 ECU gives me CEL flashes.