check engine light on, but is it?

[diggman08]

hey guys, if my key is turned all the way to on position, but not cranked the check engine light comes on. As soon as I crank the truck, the check engine light goes off.

 

can yall do a test and see if the same results occur,

 

thanks

[bdbake01]

Normal. All of my GM vehicles do this.

[nards444]

moat vehicles I have had in the last 15 years the check engine light would always flash,or illuminate for a second upon start up. normal

[SMiller]

Normal

[newdude]

Completely normal. Just an instrument cluster self test/vehicle self test at key on.

[Btuggle88]

Normal it kinda lets you know all the lights work just in case they need to come on, if it never comes on you should worry.

[POS VETT]

All vehicles with electronic powertrain control do this.

[diggman08]

all the lights do come on as a test, but then go off briefly after, but only the check engine light stays on, until cranked, then goes off. just wanted to clarify that. still norm?

[Btuggle88]

Yep still normal only abnormal if it stays on after its running.

[BigBadSierra]

Light comes on.

 

You start the engine.

 

It runs a quick diagnostic check on the engine.

 

Then the light goes out.