1994 Silverado "Service Engine Soon" Question
 

Hello, first time poster here...

I just bought a '94 Chevy Silverado. It has 130K miles on it and runs good. However, during the past 3 days, I have noticed that the "Service Engine Soon" light will come on when I let the truck sit and idle while in Park. Once I shift into Drive and while I'm driving the light is not on. But, it seems to come on each time I put it in park. I went through the drive through yesterday and idled in Drive for a few minutes and it never came on...but, when I shift it into Park, it comes on.

I was wondering if anyone has had any experience with this problem? It runs strong and otherwise seems to be doing fine...I haven't had the time to check the code(s) yet, but will in the next day or so.

Thoughts on what it might be?

Thanks.

personally if it doesnt affect the way the engine runs i would not worry about it but it would be good to get the code.

but that is strange and i have no clue what would trip it in park

maybe your altenator is bad when your parking look at your volts guage if it bonces around its eather your battery or altanator
when you drive your battery will read normal but if in park it will bounce or go lower then the middle
due to the altenator not putting out enuahg voltage to keep teh battery where it should

Could be your Alt, or voltage regulator. Get the code so you know what your dealing with. Could be something as simple as idle.

Just go by an Auto Zone or similar parts box store. The will usually run the codes for you for free, and give you a print out of it. Of course, they will also, most likely, have the part or bits you need to correct the situation.

Good luck!

the old school way is easyier and you can do it in your driveway
take a jumper wire and stick in in the a and b ports on your obd1 port under the dash turn yoru engine on not to start then your check engine light will flash 12 meaining your cpu is working
then all codes after that will be 13-80 somthing
theres a thread on here somewhere on how to do it

Yep, that'll work, too. Then you can go to the parts store to get what you need to fix it, lol