key on,engine light works.engine running light stays off.engine off and on immediately engine light will not come on for bulb check.if key is left off for about 10 seconds,and turned back to on position ,the engine light works.is it a problem or normal for this general motors vehicle?
is it normal for mil light on gmc truck to operate this way? on 2003 GMC Yukon Denali
by rebo in Charlotte, NC on January 11, 2012
ANSWER by patrick mannion on January 11, 2012
It sounds like it is working OK, it should come on with ignition key in the on position as a bulb check and to tell you the ECU/PCM gets power, if there was a fault the light would come on (or come on and flash) if there was a problem with the emission control system.