service engine soon light?

My service engine soon light stays on even after removing the Neg. battery wire from the battery, any ideas why? Thanks:banghead:

There must be a problem that triggers it to return after you re-connect the battery and start it up again. Check the code to see whats going on

What year? The PCM will store data in NVRAM for months with the power removed on most later models ('96-up).

Thanks guys for the fast reply, It's a 2001 Blazer. that just has me stumped, is there a reasonable way to check codes, My mechanic wants 70.00 just to read them. Thanks again.

Thanks guys for the fast reply, It's a 2001 Blazer. that just has me stumped, is there a reasonable way to check codes, My mechanic wants 70.00 just to read them. Thanks again.

Go to autozone or other parts store, they will read them for free, write them down and post codes. Just beware that they will try to sell you parts.

Thanks again, I'll do that and post the codes thanks guys.

Thanks guys for the fast reply, It's a 2001 Blazer. that just has me stumped, is there a reasonable way to check codes, My mechanic wants 70.00 just to read them. Thanks again.


Just to read codes is a 10 minute deal.
70 dollars is high for a 10 minute code read out.
And just the code does not say replace the part but to check it out first.

But the full diagnostic like check codes andreaqd out the computer and check fuel pressure and find out what is the problem is.
Can take around a hr.

Which deal is your mechanic doing for you?

If the 10 minute code check that figures out to 420$ hr labor.
But a full diagnostic service done right and find the problem for 70 $ is money well spent.

It's the 10 min. job MT-2500. foolishly I've payed for it in the past... But I'll have it done at autozone sooln as I can. thanks

It's the 10 min. job MT-2500. foolishly I've payed for it in the past... But I'll have it done at autozone sooln as I can. thanks


10-4 on the 10 minute codes check.
yes AZ and some other parts places will give a free code check.

But beware if there is a code the code does not say replace the part but to check it out.
As in a 02 sensor code many other things cam cause the code.
That is where you need the full diagnostic testing to find the problem.

If you get a code no post it back here for help on it or get a good repair manual that has the code repair flow chart for testing out code no.

Let us know the code no and how it goes.
Good Luck

Thanks again MT-2500 I sure will. it'll be a lil bit before I can get it done but I'll post the codes when I get them, Thanks again.

Well MT-2500 I Got-R-Done... I forgot the code but it turned out to be either a stuck Thermastat or Thermastat sensor, so I did both just to make sure.
Thanks for all the help from you and everyone else.
It most likely won't be the last time ya hear from me. lol. Just love this lil Blaser. off topic but... We just got about 3/4 of an inch of ice and 3 inches of snow and that Auto 4 WD is Great, I've never had a vehicle that had that option before. Thanks Again all for the help!!!!!!