2015 Yukon Denali stuck in lockdown

[KFPanda]

Hello banging my head against the wall on this hoping someone can help. I inadvertently triggered the theft alarm messing with the alternator cable and now I can't get it to start. From research it's the theft system, the fob will lock/unlock but console won't come on, door unlock button on handle doesn't work, steps rails don't come out and the start button won't turn the car on in any way. Pressing/holding start and I get interior lights or side collision lights but that's about it. Oh and the hazards work. I tried pulling the battery several times with no change. I have the fob sitting in the transponder pocket. Not sure what else to try...

 

[salisburyv]

on/off with the key either 3 times fast or 5 times fast just on/off then immediately start. try that/ sorry just saw its not a key

 

[Fless]

Just a WAG, but disconnect the battery and turn the lights on, pump the brakes, etc. to drain residual memory, like you would if pulling the airbag. And/or pull Fuse 29 (Content Theft) in the left side instrument panel fusebox.

 

[Doubeleive]

Hello banging my head against the wall on this hoping someone can help. I inadvertently triggered the theft alarm messing with the alternator cable and now I can't get it to start. From research it's the theft system, the fob will lock/unlock but console won't come on, door unlock button on handle doesn't work, steps rails don't come out and the start button won't turn the car on in any way. Pressing/holding start and I get interior lights or side collision lights but that's about it. Oh and the hazards work. I tried pulling the battery several times with no change. I have the fob sitting in the transponder pocket. Not sure what else to try...

either you blew one of the mega fuse on top of the battery or there is a bad ground somewhere, your issue's have nothing to with the security portion
get a meter and check the fuses on top of the battery and check all grounds
that's my best guess anyway, you are not getting full power to all modules.

 

[Doubeleive]

it will look like this or similar, each section is fused separate, if you blow out one you have to replace the whole thing, they run about $100 or so

 

[KFPanda]

either you blew one of the mega fuse on top of the battery or there is a bad ground somewhere, your issue's have nothing to with the security portion
get a meter and check the fuses on top of the battery and check all grounds
that's my best guess anyway, you are not getting full power to all modules.

I think you are right. The cable crimp touched the case of the alternator when I wiggled it and set the alarm off, seems to have blown something because now that it's dark I see that one drl stays lit with battery connected and one of the brake lights doesn't come on but both flashers do. So overall acting crazy electrically.

 

[KFPanda]

it will look like this or similar, each section is fused separate, if you blow out one you have to replace the whole thing, they run about $100 or so
View attachment 407569

How the hell do I test this thing?

 

[Fless]

With a test light or DC voltmeter.

Connect the negative lead of the test device to ground (negative battery post), then touch the VOM positive lead or test light to each threaded post or the nut on the post. Each post that has a good fuse should read battery voltage or light the test light.

 

[KFPanda]

With a test light or DC voltmeter.

Connect the negative lead of the test device to ground (negative battery post), then touch the VOM positive lead or test light to each threaded post or the nut on the post. Each post that has a good fuse should read battery voltage or light the test light.

Ok, my meter thankfully has a continuity test so I figured out there is not continuity on the 175A fuse that connects to the alternator and another cable so that makes sense. I see one unused fuse but it's only 125A, I guess it's probably not a good idea to try that one just temporarily?


*** Scratch that, 170A alternator..... what about connecting it to the unfused post?

 

[Doubeleive]

Ok, my meter thankfully has a continuity test so I figured out there is not continuity on the 175A fuse that connects to the alternator and another cable so that makes sense. I see one unused fuse but it's only 125A, I guess it's probably not a good idea to try that one just temporarily?


*** Scratch that, 170A alternator..... what about connecting it to the unfused post?

no you don't want to make things worse, get a new one.
I did the same thing once "sort of" I was installing a stereo amp and the amp was bad out of the box so when I hooked it up and turned everything on it went up in smoke and blew probably the same 170a fuse since I figured that was a good one to use for the amp, truck wouldn't start after that and I figured I was going to have replace a bunch of stuff but I started checking and found that fuse blown, went and bought a new one and thankfully everything worked.