Passlock Problem With 2000 Silverado Truck Wont Start At Random

slayer305 · December 31, 2008

Christmas eve on my way to my dads the security light came on and stayed on. I wasn't far from the house and pulled off at a gas station. I thought that if I turned off the truck and started it again it would clear the light. WRONG! LOL! Truck wouldn't start. Called the GM dealer and luckily someone was still there and told me about the re-learn key procedure. 15 minutes later I didn't do it right and had to wait again with it starting that time. It did it again that night and about 6 times since then. After looking around on the web and this site it looks like I can buy the passlock by-pass module for a remote start system and use it to disable the passlock system. $40 is a lot cheaper than the $300+ I'm seeing to replace the sensor. I assume this would work but wanted to see of someone else had done this. I have no plans for a remote start at this point but may in the future. I also found another by-pass option. It involved cutting a wire on the ignition switch, measuring the resistance between it and another wire and soldering a resistor between the two. That idea scared me a little but only being about $3.00 and someone has done it may be worth it. Any information is appreciated.

slayer305 · January 2, 2009

Bump

grosss · January 4, 2009

The passlock system works by sending a pre-set signal/resistance that is stored in the key cylinder to the ECU. Therefore the security system is built into the lock cylinder and not the key which is why you won't find a chip in the key. As long as the key can turn the lock cylinder, the ecu will get the right signal.

From what I can remember reading about, the soldered in resistor trick works, however it pretty much nullifies the anti-theft abilities of the truck. Give it a shot, if it doesn't work you can always crimp the wire back together in the original set-up and buy the box you're talking about.

Either way I'd suggest getting an aftermarket alarm system installed afterwards to give you a little more peace of mind and probably a discount on insurance (at least that's the bonus of having one installed for us here in Canada).

markw8 · December 31, 2008

Christmas eve on my way to my dads the security light came on and stayed on. I wasn't far from the house and pulled off at a gas station. I thought that if I turned off the truck and started it again it would clear the light. WRONG! LOL! Truck wouldn't start. Called the GM dealer and luckily someone was still there and told me about the re-learn key procedure. 15 minutes later I didn't do it right and had to wait again with it starting that time. It did it again that night and about 6 times since then. After looking around on the web and this site it looks like I can buy the passlock by-pass module for a remote start system and use it to disable the passlock system. $40 is a lot cheaper than the $300+ I'm seeing to replace the sensor. I assume this would work but wanted to see of someone else had done this. I have no plans for a remote start at this point but may in the future. I also found another by-pass option. It involved cutting a wire on the ignition switch, measuring the resistance between it and another wire and soldering a resistor between the two. That idea scared me a little but only being about $3.00 and someone has done it may be worth it. Any information is appreciated.

Hi. I had trouble with my 2000 while under warrenty. The security light was staying on and it was hard to start. I would have to try numerous times, and it would have to crank 8-10 seconds. This was fixed by replaceing the ignition switch. So I would be careful of what you do, without being completly sure this bypass will work. The ign. switch and this module, are they the same part?

Mark.

markw8 · December 31, 2008

One more thing. After thinking about it, and checking my key, there is no pellet in my key to be read. If your's is the same, which I believe it to be, there is no resistor to fool.

Mark.

slayer305 · December 31, 2008

Christmas eve on my way to my dads the security light came on and stayed on. I wasn't far from the house and pulled off at a gas station. I thought that if I turned off the truck and started it again it would clear the light. WRONG! LOL! Truck wouldn't start. Called the GM dealer and luckily someone was still there and told me about the re-learn key procedure. 15 minutes later I didn't do it right and had to wait again with it starting that time. It did it again that night and about 6 times since then. After looking around on the web and this site it looks like I can buy the passlock by-pass module for a remote start system and use it to disable the passlock system. $40 is a lot cheaper than the $300+ I'm seeing to replace the sensor. I assume this would work but wanted to see of someone else had done this. I have no plans for a remote start at this point but may in the future. I also found another by-pass option. It involved cutting a wire on the ignition switch, measuring the resistance between it and another wire and soldering a resistor between the two. That idea scared me a little but only being about $3.00 and someone has done it may be worth it. Any information is appreciated.

Hi. I had trouble with my 2000 while under warrenty. The security light was staying on and it was hard to start. I would have to try numerous times, and it would have to crank 8-10 seconds. This was fixed by replaceing the ignition switch. So I would be careful of what you do, without being completly sure this bypass will work. The ign. switch and this module, are they the same part?

Mark.

The module is a box that is wired into the data bus from the pcm from the way I understand it. It is a added piece that is required when a remote start system is used.

slayer305 · December 31, 2008

One more thing. After thinking about it, and checking my key, there is no pellet in my key to be read. If your's is the same, which I believe it to be, there is no resistor to fool.

Mark.

GM's Passlock system does not use a transponder key. The actual transponder is in the ignitions lock and tumblers. When the key is inserted it sends a magnetic pulse to the pcm. If the pulse is correct it then allows the bcm send the message to the fuel system. The keys only have to be cut to the correct factory depth. In my opinion its a stupid way of having a transponder system, but beats having to pay a fortune for a key.

markw8 · December 31, 2008

Ok, you've taught me something. I just wanted to make sure you didn't throw unnessasary parts at it.

Mark.

slayer305 · December 31, 2008

Ok, you've taught me something. I just wanted to make sure you didn't throw unnessasary parts at it.

Mark.

No problem, and I thank you for being here and helping. The last thing I want to do is throw money at it and it not work. I didnt know about the key and the passlock until this happend to me a few days ago. The dealer told me the passlock sensor starts to fail with age and a drastic temprature change leads to the failure with age. I had been 0-20 degrees here for several days and the day this started the temp jumped to almost 60.

slayer305 · January 4, 2009

I purchased the bypass module and hopefully it will be here next week. I didnt really like the idea of cutting the ignition harness. From what I was told from the guy at www.passlock2.com the security system still works just as it did minus the resistor based passlock. I plan on adding a alarm or remote start alarm later on. Insurance company will only find out things they are told, and I dont plan on telling them. I already have the alarm discount from the factory system. The alarm will still go off when broken into.