Wife bought a great Civic 1.5LSi, only 23,000 mls on clock. Was fine then Engine Management Light on dash wouldn't go out and car wouldn't start. Breakdown and mechanic said it was the coil so got it replaced (ouch - its part of the distributer and cost a bomd). Worked fine for a couple of weeks, then same thing happened - this time seems to be the main realy - replaced it (ouch again) and all was fine. Then a couple of weeks later, same again - light on, no spark and no fuel. Then thought we had has a EUREKA moment - immobiliser system (Foxguard). Remove this entirely and hey presto we sprung into life again.....BUT....a couple of weeks later the light came on again and would not start. No having any hair left by now, stuck it in a dealer and he rang 30 minutes later to say ECU had gone - mega cost to replace and fit (twice what I paid for the car) so said no thank you. Took ECU out and sent it to specialist who says there's nothing wrong with it.....so now I'm completely stumped.
Have tried to work out any ECU codes but instead of one little blue connector inside the green cover (to bridge the 2 wires) I have 2 grey connectors each with 2 wires, one connector slightly wider than the other. If I bridge the wires in either one the light on the dash wont flash.
Anyone got any ideas?

 

do you have the OEM ecu in the car still?

turn the key to the ON position and the check engine light will/should comeon. if it does then the ECU is getting power and is responding.
if it dosent then the ECU is Junk and it will need to be replaced.

when your jumping those harnesses your checking for codes on the CEL light. if it dosent flash then i dont htink you have any codes.

 

Did you turn the key on when you had either harness bridged like 99SI said? The light wont turn on until then.

EDIT: i didnt see the title and was asking what year Civic you had....