this is regarding to a 88 cadillac deville, if anyone knows anything about the service now light that would be much help and i would appreciate it. Thanks

Originally posted by CadillacBlue5
this is regarding to a 88 cadillac deville, if anyone knows anything about the service now light that would be much help and i would appreciate it. Thanks

They always come on. I think I may have had 1 or 2 that didn't. LOL! Could mean a bunch of things, check out your service manual, or just pull the fuse! hehe..:banana:

ok thanks hehe i figured that was the problem but wasnt sure

I had the same problem on my deville. The dealer told me that the problem was caused by using cheapo gas instead of premium. The regular unleaded had caused carbon to build up on the throttle body and the O2 sensor. It took about $175 to fix it

1 of 2 things needs to be done here:

1: Service the car and see if it goes off
2: Pull the fuse...those lights are unreliable

3: you're screwed.

That's what it ment on my 85 at least. But if it's still running all right, probably a screwy light.

If your '85 was like my '85 the light should have said......"You should have serviced the engine yesterday"


When the S.E.N. light came on, It was too late!:burn: :vomit: :crying2:

Originally posted by kcnewell
If your '85 was like my '85 the light should have said......"You should have serviced the engine yesterday"


When the S.E.N. light came on, It was too late!:burn: :vomit: :crying2:
Pretty much. It would go service soon, service now, you're walking:( . It's really bad when those two came on at the same time though. At that point I was like :banghead:.

Ah yes! The venerable HT4100...........P.O.S. I really liked that car ('85 Eldorado )....But the motor SUCKED!!!!!

Mine was in a FW coupe. I miss that car too. Put a lot of work into that thing.

to add to previos good comments. 95 deville comes with service emissions message at same time. and also comes on less since i bought the car and use premium gas. a reasonable mechanic (find one and latch onto him or her) would charge $50 labor and oxygen sensor should run about $50. key is to heat sensor exhaust mounting pipe to remove old one. good luck

This post is 4 years old! I suspect it is fixed by now.