Service Engine Soon vs. Check Engine
 

What is the difference (if any) between the Service Engine Soon light and the Check Engine light? My 93 only has a Service Engine Soon light and my 99 only has a Check Engine light. Neither has both.

Not too sure, may want to wait for a gearhead to correct me, but I think the only difference is common terminology. 93 is pre OBDII, and 99 is OBDII, so I think all the terms (SES vs CE/CES) were standardized...just a guess.

Pre-OBD-II, otherwise known as... OBD I.....

Same light though. :wink:

Does the Service Engine Soon light check for as many faults as the ODB II? I am yet to get the light to come on (it does at start up, though)....even when the car was running like crap. The one in my 99 doesn't think twice before it'll come on and off, though!!!

They mean the same thing. Yes, OBD-II has many more codes than OBD-I, and it is more advanced. It has the ability to detect faults that OBD-I cannot.

Ayup.

Incidentally, I drove an Olds Silhouette a while back and noticed that it had both a Service Engine Soon light and another that said something like "Service Vehicle Soon". One would light up _before_ I started the engine, the other would light up _after_...

My 97 says "service engine soon" so does our 00 SSEi. The 'service vehicle' soon' is for something chassis related, in the example of the Bonneville, it would be the stabiliity control system, brakes, suspension, etc.