Check Engine light problem

[roy67ss]

Hi guys,

 

I used my scanner program to turn off the SES light and clear the codes and now the light appears to be dead. It will not come on when the key is turned to on and will not come on when codes should be set. I have checked this by running it with plug wires and other wires unhooked which would gaurantee setting a code.

 

Has anyone ever heard of something like this?

 

It appears that if the light doesn't work, no codes will be retained and that the OBD part of the system becomes disabled.

 

The scanner program I am using and have used for 1.5 yrs is called Car Code. It is on my laptop and connects via serial port and an interface to the OBD port on the truck.

 

The truck is a 99 Silverado with 4.8l engine and is running normal, ie not in limp mode or anything like that.

 

If the light is burnt out, will it disable the OBD? The light is soldered onto the cluster circuit board so, not a real easy fix.

 

Is it concievable that a dealer scan tool would be able to reactivate it if it isn't burnt out?

[trekker789]

Hi,

 

Having similar issues wish my check engine light, but seems to be more inconsistent. Attempted to diagnose with similar results.

 

Just wondring if you reached any conclusions?

Sierra 1500 - 5.3 - 2003

 

Thanks

[Indy]

The light being out does not disable the system. Are you sure there is power to the OBD port? If not check the fuse, I believe it's the same fuse as the lighter.

 

P.S. I just noticed the original post is over a month old. Can someone confirm that the lighter fuse is for the OBD port also.