Hi all,

Looking for a little help. My '98 started throwing a CEL a few days ago. I did the ignition "on, off, on, off, on" and came up with codes 12 and 31.

According to the CEL thread here:

12 - Direct battery input to PCM was disconnected within the last 50 key-on cycles
31 - Evap purge flow monitor failure or evap solenoid circuit

Unfortunately, lol, I have no idea what either of those mean?? Can anyone help me out?

If I pull the battery for a while will it reset the codes?

Thank you in advance for any help you can offer.

 

The first one is nothing. The second one is the thing that clips to the passenger side motor mount. Has to vacuum hoses and a wire clip. A bad vacuum hose or a loose connection on the sensor will cause that.

 

hmmm ok ... well I guess I will check the sensor first. do you know if the hoses are difficult to change if those are the problem? I haven't noticed the engine acting weird at all. My old Laser had a vacuum leak before and the RPMs would surge and stuff all the time.

 

Just give it a look over. Chances are it needs changed. I would not change mine. You dont need it. Just so you know that the canister in the passenger side fender the black round or box thing is also part of it. Then it runs all the way to the back to the gas tank. Cant a loose gas cap also throw that light off?

 

i was actually thinking it might be a loose gas cap. I think what I'm going to do is look everything over, then pull the battery for awhile to reset the CEL and see if it comes back.

 

Exactly what I would suggest.

 

ok so I changed the oil today and while I was doing that I had disconnected the negative battery terminal. I did check those hoses and they looked tight and whatnot so I dont think that is the problem. Anyways, I reattached the battery terminal after about 30 minutes and now the CEL is not on. So I am hoping that it was a loose gas cap or something that set it off. Thanks again for your help guys!!

 

Good to hear. Post back if any problems arise again.

 

Leaving your battery disconnected resets the CEL, but it doesn't mean that the CEL is gone. Give it between 75 and 150 miles of driving before you decide it is actually gone.