Car lock symbol

[Nicolegmc]

I had to replace my battery to my Yukon. Now this light comes on and I can’t start the truck. Can anyone please help me out?!?

 

[Scottydoggs]

thats the security light, why it wont crank. try locking and unlocking the doors with the fob and manually.

if that dont turn it off id try un hooking the battery again, if that dont clear it try,

key to run for 10 minutes, then off for less then 5 seconds, back to run for 10 minutes off and back to run for a third time for 10 minutes. if you got a battery charger hook it up. ebrake on and everything inside the truck turned off. key to run for 30 minutes can kill a new battery. why the charger is nice to have. this is called a "security learn."

 

[Joseph Garcia]

^^^^^x2^^^^^

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

 

[Nicolegmc]

thats the security light, why it wont crank. try locking and unlocking the doors with the fob and manually.

if that dont turn it off id try un hooking the battery again, if that dont clear it try,

key to run for 10 minutes, then off for less then 5 seconds, back to run for 10 minutes off and back to run for a third time for 10 minutes. if you got a battery charger hook it up. ebrake on and everything inside the truck turned off. key to run for 30 minutes can kill a new battery. why the charger is nice to have. this is called a "security learn."

I just tried this and nothing happened.

 

[Scottydoggs]

I just tried this and nothing happened.

well that sucks. next id see if you got power to the small wire on the starter solenoid with the key to crank. if you do the starter has failed on you. at that point try hitting the body of the starter with a hammer with a few med blows while the key is held to run. some times you can beat em back to life for a short time.

im sure you did the relay swap deal for the starter relay already?

 

[Doubeleive]

I just tried this and nothing happened.

disconnect the battery first as noted above, while you have the cables off touch them together for a few seconds and see if that clears up the problem
if not then try the relearn again exactly as stated 3X10 minute, do not try to start it between each interval, upon completion of the last interval turn the key to off and leave it for 1 minute, the security light should light and then go out after a couple seconds with key in the run position. if it does not work then you might have a bad ignition or hall sensor, which would be odd from just a battery change but not impossible.
if it won't relearn with the key, try another spare key
if that doesn't work then you could try a mobile locksmith as they can use a device to make it relearn

**also check all your fuses there should be a security fuse, look in the owners manual about 3/4's of the way thru it shows all the fuses and what they do

 

[rockola1971]

GM Security does not stop a vehicle from cranking or starting. The security system only stops vehicle fuel delivery after 5-10 seconds of engine runnning.