Huh? Looked in the FSM and no mention of code 05...in both U-check mode (green connectors under hood unplugged) and D-check mode (green connectors plugged together) with ignition on (engine not running) I read five fast blinks on the ECU led, separated by a ~2 sec. gap. I read this as a '5', is this right? No slow blinks that would indicate a '10'...

 

I got a CEL a week ago while driving at slow speed, but it went out quick...thats what started me on this...hasn't lit since.

 

I wonder if this is a specification code, but I don't recall it ever indicating this code before...

 

89 GL 3-door dual range

wrong connectors

Those are for setting the timing

and for select monitor use

 

try the white or if you have them black

 

connectors beside the green ones

Whoa, connected the white ones and the ECU had quite a story to tell, like it had bottled up years of memories without anyone to talk to...to me this sounds like "read memory" mode

 

According to the FSM:

 

Connecting green (test mode) connectors = D-check mode (fuel pump runs intermittently)

 

Connecting white connectors = Read memory

 

Connecting both green and white = clear memory (with engine on)

 

Thanks for setting me straight on this.

Ignore single digit codes. They indicate things like automatic/manual/California equipped.