I had a post about a high idle problem I am having, and I have been unable to read codes as the SES light did not function.
i removed the dash panel today and found there was no bulb in that location. I swapped a bulb in from another slot, making sure it was a working bulb, reinstalled the panel and checked it. The light does not work.
It was suggested my ECM is bad, but could the PC board that is the back of the panel be bad? I can't check input power to that bulb holder slot with the panel in place unless I remove the top of the dashboard and even then I can't be sure I could access it with meter leads. Obviously I can't power the panel with it pulled back from the dash.
Any suggestions? How can the ECM be "bad" and the engine still run well? Is the data output to the SES bad?
Eric

 

I would purchase a hand held code reader, I dont think they are that expensive . Even if the bulb is blown in the dash you will still be able to get the codes , plus it will tell you if the ECM is bad. Eliminates alot of guess work.
SOME used car dealers are famous for pulling the plug on SES lights.

 

Well, this car has had the dash panel replaced or worked on at some time, so I am no suprised.
I will get someone to plug in a handheld reader and let me know what's up. Even if I just pay the guy to read them for me and tell me what they are, I can troubleshoot it from there. See my post "high idle returneth!"

 

You can test these flex circuit borads easy.
Just use a Ohm meter and get checking.
From in the car?
Kinda doubt it, tho.
I've even repaired the circuit borads.
Use the repair kit for the window heater lines in the back window.
Can your Flex circuit board be bad?
Can your ECM be bad, cause it's not kicking out a signal?
Tough calls.
Need other things to swap in to test.

 

you beat me to it Karl

 

I thought of that, but I have found that on this '91 when I pull the panel out, I have just the room to lay it face down on the coulnm but it looks as though the dashtop panel has to come off to completley remove it, making testing easier.
I just for now did the disconnect the battery cable thing to clear the ECM code that was causing the high idle, 2500 cold, 1400 worm. Now it's back to the nice 700 in gear when warm where I have the minimum air set.
What are some of the sensors that could cause the high idle condition? Hard to say?

 

To get the instrument cluster out tilt your wheel all the way down. It will take a little figing around with but it will come out. For some reason it is easier to get it back in. In fact mine just sliped right back into place.

 

Well I did have the wheel all the way tilted down, but it won't lock in the lowermost position. I tried holding the wheel down with my chin (my third hand is in the shop!) and wiggling it out and gave up.
When my fiance got the car, she couldn't pass inspection (VA) until the high beams worked, so I was checking this and that, and finally hit the tilt lever instead of the signal stalk and as soon as the wheel tilted up the high beam switch worked! For some reason, when it's tilted down like an aircraft stick which is how she drives, the switch is not making contact.
That and I get a BIG bruise on my leg when I jump in the car after she's been driving it and foget to first raise the wheel a click.