I am having an issue with my 1998 Chevrolet K1500 P/U. My truck wouldn't start one morning, and it it took forever to figure out the problem was the passlock security system. I looked up online and found out the 10 minute reset procedure, but after multiple failed attempts, it won't work. So then I found out how to bypass it by cutting the yellow wire and checking the resistance, then getting the appropriate resistor. The problem is when I try and measure the resistance, I don't get any reading. I'm not sure what to do next. Should I buy a new ignition switch and hope this is the problem? I hate to throw any more parts at this, already replaced the fuel pump and pressure regulator before i found out it was the pass lock. Anybody have any experience with this security system? Thanks in advance for any info.
Advice on GM's Passlock security system?
- Thread starter womcat
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Install a new ignition lock with keys. Perform re-learn.
Think you are confusing the GM systems
IIRC your 98 uses Passkey which is a transponder key unlike earlier systems like VATS that had resistor pellets on the keys. On those systems you would measure the resistance of the pellet on the key and build that value of a single or multiple resistors to match the key, then cut the yellow braided wire (two conductors) and splice in the resistor pack there (side going the the security module not the side going into the column/lock cylinder). On these it wasn't uncommon for the contacts in the lock cylinder that read the resistor pellet to fail (car wouldn't start and you would get a Security warning on the dash.
IIRC your 98 uses Passkey which is a transponder key unlike earlier systems like VATS that had resistor pellets on the keys. On those systems you would measure the resistance of the pellet on the key and build that value of a single or multiple resistors to match the key, then cut the yellow braided wire (two conductors) and splice in the resistor pack there (side going the the security module not the side going into the column/lock cylinder). On these it wasn't uncommon for the contacts in the lock cylinder that read the resistor pellet to fail (car wouldn't start and you would get a Security warning on the dash.
Originally Posted By: womcat
I am having an issue with my 1998 Chevrolet K1500 P/U. My truck wouldn't start one morning, and it it took forever to figure out the problem was the passlock security system. I looked up online and found out the 10 minute reset procedure, but after multiple failed attempts, it won't work. So then I found out how to bypass it by cutting the yellow wire and checking the resistance, then getting the appropriate resistor. The problem is when I try and measure the resistance, I don't get any reading. I'm not sure what to do next. Should I buy a new ignition switch and hope this is the problem? I hate to throw any more parts at this, already replaced the fuel pump and pressure regulator before i found out it was the pass lock. Anybody have any experience with this security system? Thanks in advance for any info.
Good luck with this. I had a nightmare with my '04 Chevy Malibu Classic, that started with the classic Passlock malfunction and ate its way into the electrical system, so the fuel pump would not talk to the computer---something like that. Like you, I paid for a new fuel pump---and in my case the labor to install it, since it was physically inside the gas tank. It did no good in the long run, and to this day neither I nor the reliable for basic service mechanic who worked on the car can say if the fuel pump was really bad to start with.
I suggest trying a new ignition lock cylinder, as suggested elsewhere in the thread. If that does not work, trade in the truck before you put another penny into it. Not kidding: My Chevy was wonderful for six years, then a money pit for its last six months.
Do not under any circumstances fall for a line from a Chevy dealer that the fix is a new (re-programmed) ECU, or whatever it's called on your truck. Chevy dealers loved to suggest that to folks who had "the problem that starts with Passlock." It might work in the short term, but before long things will unravel again.
I am not familiar with this issue on pickups, but Google fuel pump and/or Passlock problems for Malibus, Aleros and similar GM cars from late '90s to about 2005 or '06. Lots of info; not pretty---mainly because there is no clear "fix" to the problem....which manifests itself in quirky ways for individual vehicles and hapless owners. (And a real shame, since apart from this one 'little' issue these were mostly good solid daily drivers.)
Amazing we never heard more about this, from the crusaders who sued over Dex-cool and intake manifold gaskets. But anyway: Lock cylinder, cross your fingers and pray.
Good luck.
I am having an issue with my 1998 Chevrolet K1500 P/U. My truck wouldn't start one morning, and it it took forever to figure out the problem was the passlock security system. I looked up online and found out the 10 minute reset procedure, but after multiple failed attempts, it won't work. So then I found out how to bypass it by cutting the yellow wire and checking the resistance, then getting the appropriate resistor. The problem is when I try and measure the resistance, I don't get any reading. I'm not sure what to do next. Should I buy a new ignition switch and hope this is the problem? I hate to throw any more parts at this, already replaced the fuel pump and pressure regulator before i found out it was the pass lock. Anybody have any experience with this security system? Thanks in advance for any info.
Good luck with this. I had a nightmare with my '04 Chevy Malibu Classic, that started with the classic Passlock malfunction and ate its way into the electrical system, so the fuel pump would not talk to the computer---something like that. Like you, I paid for a new fuel pump---and in my case the labor to install it, since it was physically inside the gas tank. It did no good in the long run, and to this day neither I nor the reliable for basic service mechanic who worked on the car can say if the fuel pump was really bad to start with.
I suggest trying a new ignition lock cylinder, as suggested elsewhere in the thread. If that does not work, trade in the truck before you put another penny into it. Not kidding: My Chevy was wonderful for six years, then a money pit for its last six months.
Do not under any circumstances fall for a line from a Chevy dealer that the fix is a new (re-programmed) ECU, or whatever it's called on your truck. Chevy dealers loved to suggest that to folks who had "the problem that starts with Passlock." It might work in the short term, but before long things will unravel again.
I am not familiar with this issue on pickups, but Google fuel pump and/or Passlock problems for Malibus, Aleros and similar GM cars from late '90s to about 2005 or '06. Lots of info; not pretty---mainly because there is no clear "fix" to the problem....which manifests itself in quirky ways for individual vehicles and hapless owners. (And a real shame, since apart from this one 'little' issue these were mostly good solid daily drivers.)
Amazing we never heard more about this, from the crusaders who sued over Dex-cool and intake manifold gaskets. But anyway: Lock cylinder, cross your fingers and pray.
Good luck.
I don't know about your car, but on my 1999 Alero, the resistor is not in the key. The fix is to solder in a resistor and have it re-learn the new value.
Go to any Saturn internet sight type in security system problems, then be prepaired for 3 to 5 hours of reading.try saturns fans .com first.Saturn oweners have suffered this problems for years.
A new lock is a hit or miss attempt to fix this problem, and if it does fix it the problem can come back again in the future when the new lock wears.
The REAL fix for this problem is to get the bypass box that is installed when a remote start is installed.
If you are not able to install the bypass box yourself, go to a shop that installs the remote start and have them install that bypass box. You might also ask them what the price would be if they installed the full remote start system, and decide if paying the difference is worth it.
I think the bypass box has a set-up to install different resistors until you get one that is the proper resistance to make the system think it has a correct key being properly read.
What this all boils down to is that the security system has to see a proper resistance before it will allow a start. Somewhere there are two wires that if you know what two wires, and what resistance, you could just cut those two wires free from the lock, and solder a resistor of the correct value, throw some tape or heat shrink around it to keep it electrically safe from contacting anything such as the chase ground, and it would never again cause a problem.
The bypass box is just an easier way of getting that resistor connected to the proper place in that poorly designed security system.
The REAL fix for this problem is to get the bypass box that is installed when a remote start is installed.
If you are not able to install the bypass box yourself, go to a shop that installs the remote start and have them install that bypass box. You might also ask them what the price would be if they installed the full remote start system, and decide if paying the difference is worth it.
I think the bypass box has a set-up to install different resistors until you get one that is the proper resistance to make the system think it has a correct key being properly read.
What this all boils down to is that the security system has to see a proper resistance before it will allow a start. Somewhere there are two wires that if you know what two wires, and what resistance, you could just cut those two wires free from the lock, and solder a resistor of the correct value, throw some tape or heat shrink around it to keep it electrically safe from contacting anything such as the chase ground, and it would never again cause a problem.
The bypass box is just an easier way of getting that resistor connected to the proper place in that poorly designed security system.
I have not looked, but YouTube might have something showing you how to install the bypass box, or the resistor.
Our old '99 Malibu had a problem with this. Every so often, it would cut fuel/spark during start up and make me wait 10 minutes to try again. All the while the Security light flashing at me. I never really "fixed" it - I did squirt some white lithium grease spray into the igintion key slot, worked it around, and never had a problem again.
Was it the right solution? Probably not. But it worked for me!
Was it the right solution? Probably not. But it worked for me!
Originally Posted By: Virtuoso
Our old '99 Malibu had a problem with this. Every so often, it would cut fuel/spark during start up and make me wait 10 minutes to try again. All the while the Security light flashing at me. I never really "fixed" it - I did squirt some white lithium grease spray into the igintion key slot, worked it around, and never had a problem again.
Was it the right solution? Probably not. But it worked for me!
Yep; this will work---for awhile. I used contact cleaner and cleaned it off with the tissue paper from a shoebox. That buys a few months....
Our old '99 Malibu had a problem with this. Every so often, it would cut fuel/spark during start up and make me wait 10 minutes to try again. All the while the Security light flashing at me. I never really "fixed" it - I did squirt some white lithium grease spray into the igintion key slot, worked it around, and never had a problem again.
Was it the right solution? Probably not. But it worked for me!
Yep; this will work---for awhile. I used contact cleaner and cleaned it off with the tissue paper from a shoebox. That buys a few months....
Thanks everyone for the advice. It is definitely the passlock or passlock 2 system, as there is no chip in the key.
I think I think i will hook up a resistor first just to try it. I'm not getting any resistance from the cut yellow wire through the ignition switch to the black wire.
Also this might or might not be related, but all of this started because of a dead battery. A few weeks ago my A/C stopped working. I'm not getting any power to the A/C clutch from the dash switch, and it's not because of the low pressure switch either. A mechanic that looked at it was stumped, and thought maybe there was a short or break in the wire somewhere. I was getting ready to leave on vacation so I hooked up a toggle switch so I would at least have AC. When I got home I forgot to turn it off so overnight it ran the battery down. Next day I hooked up the battery charger, but it hasn't restarted since. This is getting very frustrating.
I think I think i will hook up a resistor first just to try it. I'm not getting any resistance from the cut yellow wire through the ignition switch to the black wire.
Also this might or might not be related, but all of this started because of a dead battery. A few weeks ago my A/C stopped working. I'm not getting any power to the A/C clutch from the dash switch, and it's not because of the low pressure switch either. A mechanic that looked at it was stumped, and thought maybe there was a short or break in the wire somewhere. I was getting ready to leave on vacation so I hooked up a toggle switch so I would at least have AC. When I got home I forgot to turn it off so overnight it ran the battery down. Next day I hooked up the battery charger, but it hasn't restarted since. This is getting very frustrating.
Good luck, but talking from experience, it WILL come back.
Originally Posted By: Propflux01
Good luck, but talking from experience, it WILL come back.
It should NEVER act up again. He soldered the resistor in, and it will last the life of the vehicle, without changing the resistance because it now is not using the key or the key resistance reading.
The solder a resistor and learn is a much better fix than putting in a new lock, that will eventually go bad.
Good luck, but talking from experience, it WILL come back.
It should NEVER act up again. He soldered the resistor in, and it will last the life of the vehicle, without changing the resistance because it now is not using the key or the key resistance reading.
The solder a resistor and learn is a much better fix than putting in a new lock, that will eventually go bad.
Originally Posted By: JimPghPA
It should NEVER act up again. He soldered the resistor in, and it will last the life of the vehicle, without changing the resistance because it now is not using the key or the key resistance reading.
The solder a resistor and learn is a much better fix than putting in a new lock, that will eventually go bad.
Should is the key word. I've personally dealt with Passlock. Just commenting from experience.
It should NEVER act up again. He soldered the resistor in, and it will last the life of the vehicle, without changing the resistance because it now is not using the key or the key resistance reading.
The solder a resistor and learn is a much better fix than putting in a new lock, that will eventually go bad.
Should is the key word. I've personally dealt with Passlock. Just commenting from experience.
Didn't have time to read all the posts, but if you go to a stereo install place, they should be able to install a remote start for under 250 bucks. This will fix the problem permanently.
Our 2001 Impala had a remote start installed on it when we bought it used about nine years ago, and (knock on wood) it has never had any problem with the secutity, probably because the remote start is already working around that problem.
Soldering a resistor in should even be better than a remote start box bypass, as the resistor is actually soldered to the wires, instead of relying on any connector at a bypass box. However there probably still is a connector from those wires to the original security system. And that connector could (but brobably will not) cause any problem in the future.
Soldering a resistor in should even be better than a remote start box bypass, as the resistor is actually soldered to the wires, instead of relying on any connector at a bypass box. However there probably still is a connector from those wires to the original security system. And that connector could (but brobably will not) cause any problem in the future.
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