How do GM cars determine when the 'Change Oil' light should show?

[GreenGhost]

It happens frequently (Olds Intrigue). Usually after about 2500 miles after a change, but it varies. Anyone knows how it works? A sensor, dates, mileage??

I learned how to reset it (pressing the throttle 3 times w/ ignition on), but I'd like to know how it works...

Thanks!

 

[Heisenberg]

I think the newer ones use a combination of time, driving conditions, engine data, etc. to determine how much wear the engine has experienced. That's what the manual to my GTP says anyway (it displays mine as a percentage).

 

[Zenmervolt]

My guess is a combination of mileage and driving conditions.

ZV

 

[MikeMike]

yea, thats what it says in the manual.

takes, driving conditions, weather, mileage, and what type of driving you have been doing.

MIKE

 

[ElFenix]

the original ones only came on a pre-specified mileage after the last time the thing had been reset