ok.. so i have had a problem with my mil (check engine light)

since i played about with my idle air control valve, the check engine light intermittently appear some time for a few days some times hours, then goes off for a few hours or a few days. checked with a reader i got from the net, it connected fine but came back with no codes, and said that the mil was off, when it wasnt....

any ideas?

:-s

it doesn't read any codes, or there aren't any codes?

message returned

"No Codes"


reader connect fine and finds protocol and then "reads codes"

returns "no codes"

also says check engine light is off

hmmmmmmmmmmm, ihate doing this, but disconnect the battery. wait to a count of twenty, then turn the ignition on, this lets any residual power out of the system. reconnect battery and start car. let it run through the precheck, drive around the block for about twenty minutes, then check again. oh, remember the radio code. i think that should do it.

tried it about 3weeks ago, let the battery off for an hour, light still on at restart.

This happened to me as well, once.

The reader that you have is incompatible to the car. I used another reader or a different make and voila! 1 error code found. Fixed the part and the light went off, till today. Well, actually some other error came about after that.

Anyway, try a different reader, of a different maker.

please recommend a reader that is compatible.... and a link would be helpful too.

seems odd that it can connect and recognize what protocol to use.


sean

I couldnt remember the first one that i used, that couldnt read the codes though operations showed that it was OK.

But the second try was with a reader called MemoScan.

I had a '94 with a cel (check engine light -- not sure what a mil is) that wouldn't go off no matter what I did. Every time I checked all I got was a 'no fault' code and nothing else. I tried to reset it and it wouldn't. The answer I got from a few people was basically "well, they do that sometimes."

The car ran fine, got 27+ mpg on the highway, and I had no problems with it. I eventually sold it, with the light still on.

Probably not the answer you were looking for, right?
Good luck.

I'm willing to bet 1 cent that if you were to use the Volvo Scanner Tool, you'd be able to read the error, no matter what it is. And you'd be able to delete it too...

But the stubborn error codes will just return, as you exit the dealers' front gates, and after you paid the charges.
:)

just to add some thoughts to this...the problem started after a mechanic looked at my car and reconnected a hose that had come lose on the idle air control valve. so the only thing i can think of is a vacuum leak. can any one tell me where to look, or supply a pic?
only thing thats strange is why would the light be going on and off in such a fashion

Sean,

Firstly, what does the error code say?

Secondly, the two hoses to the IACV can get hardened and have cracks over time. I just replaced my top one last month. Also check the bottom hose that connects to the bigger one to the throttle body.

The rest, you have to look what the error says...

lol like i said the reader i have returns no codes

note: to reach these do i need to remove any parts or is it something i can just reach in for? i can check the T.B. one, but not sure where the iacv actually is

*slaps forehead*
Argh, sorry about that... My co-worker in the next cubicle got a hot date last night, and the perfume was more than my brain can handle to think straight. HEHE...

Anyway, in between the radiator and the intake manifold, is the throttle body, towards the right. Its covered by a plastic casing, helb by a crew on top. Remove the screw and you'll expose the vacuum tree, the throttle-disc and the IACV.

The Idle Air Control Valve is a metallic 'bottle-shaped' thingamajig, that is connected at the one end, to the electrical system, and at the other end, is separated into input/output outlet 'hands' that are connected with rubber hoses. 1 hose goes into the vaccuum tree on top, and the other connects to the TB hose.

Check both hoses for small cracks, especially if they are already hardened due to long-wear. Start with the mouth, usually cracks begin there.

While you're there, remove the IACV, and clean the insides well with a carbon-cleaner. May need to slowly twist-turn-push the bottle out from the rubber holder. Needs patience.
:)

Good luck.