Quick Stupid Question

[mespock]

If you get a CEL, is the only time you can check for the problem is when the light is on?

I've never had a CEL on any of my vehicles.

I've started to get a CEL on my 95 but only after I've gone over 70 mph.

If I slow down to 60 mph the light goes off. I'm assuming that it could an O2 sensor. Car doesn't have any issues while driving over 70 even if the light is on.

Any Ideas?

 

[torquemonkey]

It should be stored in the computers memory.

 

[Frogman]

The PCM will store codes that do not throw a CEL, so yeah, it's a good idea to check for codes now and then.

 

[mespock]

Ok, I thought something should be stored, but then I thought I read in a thread a while back that you need to take it in while the CEL was on.

Thanks.

 

[Frogman]

Well yeah, the PCM will store some codes that do not throw a CEL.

A perfect example of that is after you hit the speed governor. It throws a code saying something to that effect. I don't even know if a commercial scanner will pick that up. The NGS testers will pull that code.

Now, a lot of non CEL codes can and are pulled by a generic code reader, don't get me wrong.

 

[Frat-man-du]

Well yeah, the PCM will store some codes that do not throw a CEL.

A perfect example of that is after you hit the speed governor. It throws a code saying something to that effect. I don't even know if a commercial scanner will pick that up. The NGS testers will pull that code.

Now, a lot of non CEL codes can and are pulled by a generic code reader, don't get me wrong.

no kiddin...it actually tracks that you attempted to over-rev the engine...sounds like something my insurance company would love to download.

 

[Frogman]

I don't think it keeps track of engine over-revving, but it does keep track if you've touched the vehicle speed governor.

edit: I guess it does keep track of engine over-revving too. Never noticed that.

This is off of my NGS tester before removing the Top Speed Governor

 

[MarkVIII93]

On OBD1 cars you can only get the code when the light is on. Unlike OBD2 where the computer saves everything.