what makes the oil change light come on? mine used to come on every 5k miles(the first 10k i had it-changed at 3k ever since). day before yesterday change oil light comes on at exactly 3k since the last change. whats up with that?

 

They probably didn't reset the light when you had your oil changed previously. Just turn the key on with the engine off, and mash the gas 3 times, and wait for the change oil light to flash. That's how to reset it.

 

My truck takes 5 times......

 

5 times in 3 seconds.

I'm not sure what it actually looks at, but it's some type of calculation that the PCM deos taking into consideration: mileage, engine hours, avg rpm over a specified time, cold starts, and a couple of other things.

 

thanks guys, wasnt worried about it or anything, just curious

 

that light comes on whenever the computer deems it necessary to change your oil....it will vary depending on how you drive the truck

 

Your vehicle has a computer system that lets you know when to change the engine oil and filter. This is based on engine revolutions and engine temperature, and not on mileage. Based on driving conditions, the mileage at which an oil change will be indicated can vary considerably.

Also if you overheat your engine you could go from 100% oil life to Change engine oil.

As far as resetting goes:
Turn the ignition key to RUN with the engine off.
Fully press and release the accelerator pedal three times within five seconds. If the OIL LIFE RESET message flashes for 10 seconds, the system is resetting.
Turn the key to LOCK.

 

3 in 5, 5 in 3 ahhhhh it'sallthesamething! Wasn't sure on the mileage. I did know it was a PCM calculation. Thanks for a better explanation.

 

I was talking to a GM guy at their exhibit last September at the O'Reilly Nats at Ennis about the OLM and other things. He said it counts engine starts and compares the intervals to the mileage accumulated. If the driver does a lot of short trips,the change msg comes on sooner. This is in addition to what the other guys have said about it.

 

It actually has nothing to do with mileage accumulated.. If anyone has a 2004 or 2005 owners manual I believe it states in their.