service engine light

2000LTZ71 · June 3, 2002

Hey guys,

I have a question. last thursday I got into my truck in the morning and drove to work and nothing was wrong, at lunch I go out to the truck and start it up and the Serive Engine light came on. Stayed on for a couple days and then one morning I go out to take a ride and the light was off again. what would cause this light to come on for a few days and then just go away again?

thanks in advance

MarkD · June 3, 2002

It could be many, many things. Did any other lights come on? Notice any problems? Spark knock?

If it went off, I wouldn't worry about it. Are you still under warranty?

2000LTZ71 · June 3, 2002

No driving problems at all and no other lights came on. I do have a warrantee but it's an extended warrantee that I bought when I bought the truck. Not sure what it covers really. I have to check that out. I'm not going to worry about it until it happens again though.

TomEllis · June 3, 2002

Here's a wild question, did you just fill up with gas the day the light came on? and then fill up again later and it went off?

There is a sensor in the gas fill tube that senses if the cap is not put on tight and it will turn on the service light. Make sure that you put the cap on tight and make it click a few times after.

besides that I do not have another answer.

Tom

2000LTZ71 · June 3, 2002

That's interesting. I didn't do those things but that's the first time I've heard about that situation. Thanks for your reply's.

Roofer · June 4, 2002

I had the same happen to me. I figure it was a batch of bad gas. It hasn't come on since I got gas at a different station. In the owners manual it states a few different possibilities. Bad gas and the gas cap not being on tight are two of them.

Tobes · June 4, 2002

yeah....that light normally has to do with the emissions system. Could have been bad gas or even a gas cap that was not tight. Todays tanks like to keep a slight positive pressure. I guess that keeps the fumes from getting out....I might be totally off, but that is what I heard.....As long as it went off it should be OK

THE BIGPUNN · June 4, 2002

my understanding with the gas cap, is that the fuel system is under pressure. the cap being loose or engine running during fill up can cause the light to come on indicating the cpu is senses a problem and is adjusting for compression or pressure trouble. the light will come on for an many different problems. cpu can get used to one brand of fuel and the light can go off indicating a spark knock during the cpu adjusting for a new gas. even driving on "e" can cause the light to come on! if the light went out no foul. sometimes taking off the neg battery cable for a while will reset the cpu and cause the light to go out.

2000LTZ71 · June 4, 2002

That's good to know, I have fueled up before with the Truck running. I guess I won't do that anymore, it's safer that way anyway. Thanks guys for all your Reply's.