Help.

Gmc lover101 · March 27, 2018

I have a 2000 gmc Sierra. And it will start up for one second and shut right off. I reset the anti theft in it it'll run for 5 mins and shut right off. And trip the anti theft. I tried everything.. I even bought a new computer. It's still tripping the anti theft. I noticed the wire that goes to the haul bottom is ripped. Could that cause it to flip the anti theft.i need help.i don't know what else to do. I changed the ignition cylinder. The passlock. Everything in it. I don't know what else to do.

carnau · March 27, 2018

No the tow haul buttons will not cause the theft to set. Lets see what we can figure out. What codes do you have in the vehicle? This system is a pretty strainght forward system.

You have the Key which goes into the cylinder which is inside the Passlock. The passlock sends a resistance value to the Body control module which sends signal via Class 2 to the PCM.

So lets get down to the nitty gritty.

If you just want the vehicle to crank and run and you're not worried about theft. Just buy a bypass (which is cheap) But if you want to we can run though the system and I will help you figure out exactly whats wrong.

Bypass - https://amzn.to/2pK6YwR

Gmc lover101 · March 29, 2018

Idk. I paid 750$ so far trying to fix the issue. At first I thought the fuel pump was bad so I replaced it then the sending unit.then the fuel filter then I looked. And saw the security system was tripped. I let my friend borrow the truck and he ****ed the drive shaft up someone how and I had to replace the drive shaft in it. Turned out my friend put a Chevy key in it and was able to start it somehow.. But it's a gmc. Anyways. All I know is I need to get it started back up. I believe the wires that goes to the passlock on top of the key cylinder are busted. So I might go down to the junk yard find the same exact wires and and buy it. So I can get that out of the way. I think the housing might just be busted. So I looked up online allot of people say just to soulder it. And it'll fix the issue. But in a'll honestly I just want to by pass it all. I live in the middle of no where I'm not worry about anyone trying to take my truck.

sefiroxx · March 29, 2018

Bypassing the resistor check is a common action in Cadillac forum. Find the pair of wires that go up the column to the the resistor check of the cylinder. Cut below the dash. Measure resistance of the resistor on the key. Find a matching resistor(s) and solder the resistor(s) between the wire pair.

Also, if your friend used a different key, then it's likely that someone has already done the bypass. It's possible the bypass wire connections are failing.

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carnau · March 29, 2018

9 hours ago, sefiroxx said:

Bypassing the resistor check is a common action in Cadillac forum. Find the pair of wires that go up the column to the the resistor check of the cylinder. Cut below the dash. Measure resistance of the resistor on the key. Find a matching resistor(s) and solder the resistor(s) between the wire pair.

Also, if your friend used a different key, then it's likely that someone has already done the bypass. It's possible the bypass wire connections are failing.

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This isn't a resistor key.

sefiroxx · March 29, 2018

Sorry, carnau mentioned a resistance value being passed so I thought it was in the key. If there is a resistance value, then. . . . Well, I would be guessing. . . Never mind.:-)

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