check engine

[rossi]

Hi I have an 04 LLY a while ago the head gaskets went so the motor needed to be fixed. Since that time on star keeps telling me I have an engine problem that requires attention. The problem that they refer to is no power to check engine. They are right as when I go to start the truck I do not see my engine on the gauges. Any ides the mechanic that did the work does not seem to be too interested in locating the problem.

 

[BlkMax]

Does the engine run? Did you have the head gaskets fixed?

 

[rossi]

Yes like I said had it rebuilt and engine runs fine just no power to check engine light.

 

[BlkMax]

Sorry, I am trying to understand....

Is the check engine light not coming on when you put the key in the on position, or is your instrument cluster not working (gauges not coming up)?

Does the instrument cluster have any power at all?

 

[rossi]

The check engine light does not come on when I turn on the key. Air bags seat belt, coil comes on but no check engine light

 

[DAVe3283]

Here is the GM diagnostic process for your 2004 LLY. Hopefully this helps.

Basically, it seems if your instrument cluster is getting power, then it is a problem with the harness from the cluster to the ECU. You might want to look for pins that are not seated properly in the ECU connectors.