I had '98 K1500 that did exact same thing. I installed the VATS bypass myself, took me maybe two hours tops, and that included running to Radio Shack to buy the resistor. After that, my truck was perfect. I sold that truck about 6 years ago, I'm pretty sure it had remote start. I typically have remote start put on every vehicle.

The bypass is so cheap and easy.... honestly, if this was my truck, I would start with that, just because it's so easy.

Forget about taking it to dealer, on mine they wanted to install new wiring harness, it was ridiculous, and they still weren't sure it would fix. They wanted over $1,000.... I fixed it myself for $2

You have me curious about the remote start actually incorporating a bypass. I did not think the remote start installer would have to do that (remote start wont allow anyone to drive off, they'd still need a key), plus I would think they'd be hesitant to monkey around with stuff like that. Maybe call the installer and ask.

Bottom line: if this was my truck, I'd bypass that baby and see what happens. I betcha it would be fixed. Please keep us posted. These VATS issues are always interesting.

 

MORE INFO that I failed to include in OP: It cranks but does not start. Key is standard without resistor and tried spare key, but it also happens without a key (remote starter). Truck is the base model without door locks or alarm.

You have me curious about the remote start actually incorporating a bypass. I did not think the remote start installer would have to do that (remote start wont allow anyone to drive off, they'd still need a key), plus I would think they'd be hesitant to monkey around with stuff like that. Maybe call the installer and ask.

Thank you very much for replying.

I could be totally wrong as I did not install the remote starter myself. However, if the remote is going to start the vehicle without a key, I would think that it must have a built-in electronic bypass in order to get around the VATS, since you're not using the physical key. How else? As far as not being able to drive off, that's because the remote start kills the vehicle if the brake pedal is touched while the steering column remains locked, not because VATS is still engaged. Again, only as far as I know, and I could be wrong.

Since my problem has happened on both scenarios, several times with a normal key and once while attempting a remote start, I'm thinking that it's some kind of intermittent wiring issue. Maybe the three simultaneous codes, P1631, B2960, and B2961 are a clue for something? When Googling this issue, it seems that others have had a hard failure where they couldn't get the car started without a re-learn, and they have not had all three codes.

I'm just hesitant to install another bypass without being able to better determine what's wrong first.

 

Is it an aftermarket remote starter?

 

Just to throw a guess out there: I would replace the batteries in the remote. They may be getting weak and the signal might be weak. In all honesty, I have no idea if the signal is sent in a way that could happen, or if its even possible, just throwing out a guess on a cheap possible fix.

I've never had this issue on my Silverado, but I did on a Colorado about 15 years ago. Can't recall how it got fixed. This isn't a common issue on the silverado. You might find better information for a different model.

 

Is it an aftermarket remote starter?

Yes. It's a Code Alarm model CA 420A installed at a shop by the previous owner. The remote starter is functioning normally as far as I can tell, other than triggering the security light on the one occasion.

Looks like it has some kind of a VATS bypass...

GREEN w/BLACK: Pulsed Ground Output Before Start
The GREEN w/BLACK wire will provide a 1 second 300mA pulsed ground output 1.5 second before the remote start system activates as well as when the transmitter is used to unlock/disarm the system. Typical use for this output would be to disarm a factory theft deterrent system to prevent false triggering of the factory alarm when the Remote Start system engages.

The other times I've had the security light problem, I was not using the remote starter.

 

Just to throw a guess out there: I would replace the batteries in the remote.

I apologize for my poorly worded posting. Just to be clear, I don't believe the remote starter is failing and it's not what I'm complaining about. It only triggered the security light one time. It has never failed otherwise.

The problem is happening mostly when using the physical key, but also one time when using the remote starter. Truck won't start until after 10 minutes.

And occasionally when driving: Security light comes on, but truck continues to run and light clears on restart.

 

Just to throw a guess out there: I would replace the batteries in the remote.

I apologize for my poorly worded posting. Just to be clear, I don't believe the remote starter is failing and it's not what I'm complaining about. It only triggered the security light one time. It has never failed otherwise.

The problem is happening mostly when using the physical key, but also one time when using the remote starter. Truck won't start until after 10 minutes.

And occasionally when driving: Security light comes on, but truck continues to run and light clears on restart.

No, you're good, and definitely provided better information than most. Yeah, definitely sounds like Passlock. Best I can recall, I think its something about how the ignition cylinder is worn down, might even be the key worn down. At this point, I'm probably making this diagnosis worse.

 

Yeah, definitely sounds like Passlock. Best I can recall, I think its something about how the ignition cylinder is worn down, might even be the key worn down. At this point, I'm probably making this diagnosis worse.

No worries. At first I was leaning towards that too, but I would think that if it was simply a worn out ignition switch or key, then it would not have also failed when using the remote, which completely bypasses the ignition switch and key.

 

Another thought on this issue:
Do you have multiple keys? If so, maybe one key would work better than the other.

 

Another thought on this issue:
Do you have multiple keys? If so, maybe one key would work better than the other.

I do, and I've tried spare key when stranded. Since the problem has happened both with ignition switch/key as well as with remote starter, I would think that would eliminate both things as the source of the problem?

 

Sorry, I don't quite understand your context there........
does the problem occur (consistently) with both keys?

 

The problem has occurred with my main key as well as with no key at all (remote starter).

I have a spare key but since the problem also happened once while remote starting with no key at all, I ruled out ignition switch and key entirely.

 

Ahh, well, try the spare key just for the heck of it. It costs nothing....

 

I am here for the same issue. Mine does not have remote start, but I have read this is a temporary fix. I wouldn't think too much about the remote start on your truck, it seems that may have been a fluke possibly. When key goes in, the message center flashes with the battery and security light. When it is on and driving, the light will sometimes stay on the whole time or turn off and on but stay on when it does come on. I have installed a new lock cylinder thinking that was the problem would it did help a little bit because the issue was not happening everyday, now it happens maybe 1 time a week. I have to sit and wait at least 10 mins waiting for it to reset and it usually starts right up. Overall for my truck I have narrowed it down to the passlock sensor going bad or some wiring that needs to be cleaned up. If your vehicle isn't doing any strange things like unlocking randomly etc it isn't the BCM. More than likely your sensor is bad or some wiring needs to be cleaned up or replaced. I have also read that doing the resistor bypass also helps solve the issue. I would definitely try checking wires and clean up any burnt looking wires with some fine sandpaper to see if that does the trick. If not, do the bypass as that is the next cheapest fix. I'm having my husband try these few things out this weekend and hopefully can follow up with some good news.

 

The bypass is so cheap and easy.... honestly, if this was my truck, I would start with that, just because it's so easy.

So since posting this thread and getting my truck home, whatever the root cause, it's failed hard and the truck will not start at all... won't start with remote starter and will not start with a key. Waiting 10 minutes does nothing.

Yes, even though the remote starter has a VATS bypass feature, I believe there is something else wrong and now I'm exploring disabling VATS entirely and permanently. Maybe I'll find a wiring issue, but if I cannot, I want to do a VATS bypass so I can just eliminate that.

My truck key does NOT contain a resister in the key... just a standard key that I can get cut for $2 at any hardware store. It's a 2000 model, transition year, with the newer body style. Is that Passlock I ? There are a lot of conflicting videos out there and different versions of Passlock. Can you point me to a reliable resource for the proper bypass method for a 2000?

 

I have the VATS repair schematic for my '98 K1500 Silverado, but that (VATS) won't work for yours (Passlock). It's probably been 10 years since I did the VATS bypass. That seemed much more straightforward and clear than the Passlock.

I've been looking on YouTube and there are quite a few videos about this issue. There also appear to be a fair number of different approaches you could take. I currently drive a '03 Silverado, but it seemed a little different than some of the videos, I do not have the big SECURITY light in my instrument cluster on the left side, so the issue is definitely a tad confusing.

So, IMHO, you could educate yourself by watching some videos, making sure the fixes you were interested in had similar instrument cluster to yours. Then select one of those methods and go for it, but read the comments first, to see how the guys made out. Take pictures of the whole process as you do it, that way you can return it to stock and try another method in case the first attempt fails. I've had astonishingly good luck utilizing YouTube for stuff like this. And another good thing is: it looks like you could easily try most of these methods without ruining anything, so if method 1 doesn't work, try method 2, and so on.

 

I've been looking on YouTube and there are quite a few videos about this issue. There also appear to be a fair number of different approaches you could take. I currently drive a '03 Silverado, but it seemed a little different than some of the videos, I do not have the big SECURITY light in my instrument cluster on the left side, so the issue is definitely a tad confusing.

Thank you for your reply. The multitude of conflicting YouTube videos and the lack of online information about how to determine Passlock version is the whole reason I came to this forum.

Since I am presently stranded at home with it, I plan on taking the column apart to look for obvious issues and then attempt a re-learn procedure.

 

I would be tempted to try this method in the video below (be sure to watch the last two minutes, haha). I watched the whole video and I posted a comment/question about the little $30 piece that he spliced in.... was it a resistor or just a piece of wire? If it's just a piece of wire, I think I might try it on my own truck for a little preventive maintenance.

Have you tried any of the assorted methods yet?

 

Lessco Electronics has a ton of YouTube videos about Passlock. He seems to really know his stuff. He has a store on eBay: https://www.ebay.com/str/lesscoelectronics

Might be worth sending him a message to see what he has.

EDIT: I sent the guy at Lessco Electronics a message asking about a bypass kit for my truck. I want to do it before it fails. I will be sure and post his response.........................

 

I would be tempted to try this method in the video below (be sure to watch the last two minutes, haha). I watched the whole video and I posted a comment/question about the little $30 piece that he spliced in.... was it a resistor or just a piece of wire? If it's just a piece of wire, I think I might try it on my own truck for a little preventive maintenance.

Have you tried any of the assorted methods yet?

Thanks for the video. Now I am thinking I have a Passlock II.

I did not try any of the methods. I'm hesitant to just start clipping wires based on any of the videos I've seen. I've learned a lot from YouTube experts in the past, but so far on this issue, none of these Passlock videos seem to be based on expert opinion. Just people hacking around without real knowledge or explanation. I found one expert who clearly explained the various Passlock modes but nothing about how to fix or bypass.

So anyway, I got it running today. I did a standard 30-minute re-learn procedure. 10 minutes in ON position, then OFF for 15 seconds, then try to start. Repeat three times. It started after third attempt. Maybe the hall-effect sensor drifted out of spec and a re-learn was all that was needed. It's my understanding that the Passlock module and the BCM can get out of sync somehow over time... maybe because of a worn out ignition switch?

Time will tell and I'll update this thread as needed in the future.

Thank you everyone.

 

Well, the joy didn't last. Tonight, I got the "security" lamp again while driving, which does not stop the engine, but it means there is still a problem somewhere.

According to what I've managed to figure out, the various Passlock bypass solutions that involve cutting wires and/or installing resisters are not a true elimination or bypass. It's just a bypass of the ignition switch. At this point, I don't even know what version of Passlock is on this truck or how to determine.

Please, looking for anyone with some solid information about how to troubleshoot or bypass the 2000 Silverado Passlock. Meanwhile, my YouTube and Google research continues.

Thank-you!

 

I contacted this guy below (Richard Berger). He has a old web site with some Passlock solutions here: http://www.bergerweb.net/

I sent him an email about your truck (2000 Silverado with remote start).

Below is his reply:

"All solutions are off the table as long as there are aftermarket remote start, or aftermarket alarm systems. All of those systems modify the Passlock wiring, and most are not documented. If you have the installation manual for the remote start, you may be able to remove the wiring for that system, and modify the original G.M. using a resistor in the circuit. If you have any experience in electronics, I would suggest you start by getting a shop manual for your Silverado. I believe the online manuals from AlldataDIY.com are your best bet. The contain the theft control wiring diagrams, and a subscription is less than $30.00"

If it was me, I'd offer to pay the guy $50 or $100 for some guidance (if this isn't enough guidance already). I would certainly start by trying to remove the remote starter and return the system to stock. If you're lucky, you have the remote starter instructions. If you can do that, then it sounds like this guy has a solution. Hope this helps.

 

I contacted this guy below (Richard Berger). He has a old web site with some Passlock solutions here: http://www.bergerweb.net/

I sent him an email about your truck (2000 Silverado with remote start).

I really appreciate the effort you put into this and it was very educational.

It seems that all the confusion out there stems from the fact that people are conflating the terminology... VATS, Passkey, Passlock, etc. and all the various versions of these systems used on GM cars and trucks over several decades.

1. I have a 2000 Chevy Truck... which means this can only be a PASSLOCK II system. There is NO resister in the key and the head of the key does NOT contain a radio transponder. There is NO special computer or Passlock "box" under the dash. The Passlock II system is comprised of a hall-effect sensor system containing a specific resistance value that is sent back to the BCM when the key is turned.

2. In order to use a remote start without tripping the Passlock II security system, it must be installed with a relay and resistor or some other type of bypass that tricks the Passlock II system into thinking a key is turning the lock. Electrically, this is the same as the resistor bypass being installed between the two wires except that the remote start is using a relay to temporarily remove the ignition switch sensor and insert a resistor into the circuit.

3. The resistor value (resistance measured when the key is in the run position) needs to be within 5% of whatever value is stored in the BCM. Otherwise, you would need to do a re-learn procedure. Many sources are saying "any value" for this bypass resistor (and do a re-learn) but it needs to be within a range, and right now I cannot locate the values of the range. It's a moot point as I think getting as close as possible to the actual measured value would be best.

• I also found this article online. Note that the bypass circuit diagram on that site incorrectly shows the resistor connected to the key switch instead of the BCM. It's also claiming that the Passlock II needs to be reprogrammed after loss of battery power even when the resistor is permanently installed. What if your resistor matches the original value from the factory programming? After loss of power, does it just revert back to the factory value? I try to avoid loss of battery power since it really messes up the custom settings in my aftermarket stereo.
  [/*]
• Another article about Passlock, but this one contains a list of vehicle models/years.
  [/*]
• Article here about the various Passlock versions.
  [/*]
• Article about how Passlock works
  [/*]
• This article claims "all GM trucks from 98-on" have Passlock
  [/*]
• Passlock II wiring diagram[/*]

At this point, since doing a re-learn, I have had no failures that have stranded me. However, there have been several instances of the security light coming on while driving or right after starting the truck, both with and without using the remote start. This tells me that something is likely wrong in the remote start security bypass wiring. The shop that installed this remote start had done some pretty shoddy wiring on the trailer plug and aftermarket radio so nothing would surprise me. So far, I've personally rewired everything this shop has done except the remote start (they didn't even bother to install the hood safety switch).

Once winter is over, my plan is to inspect the wiring of the remote start to see how it implemented its bypass. Then I will read the resistance of the existing ignition switch circuit and install a permanent bypass resistor of the same value. Ideally, if I can match the resistor value, I can avoid a re-learn, and hopefully any future relearns every time the battery goes dead. At this point, with a permanent bypass installed, I can remove whatever bypass is being implemented by the remote start since the resistor is effectively telling the BCM there is a key inserted at all times.

I will post updates as needed. Thank you Chevy-SS for sending me enough information to fill in the gaps.

 

On my 02 that I got used, I spent several hours removing about a hundred flippin' Scotchlocks and taping up wires to remove an aftermarket alarm and remote start.
One thin that could be said for the alarm is that it would 100% eliminate theft, because the truck wouldn't run. I bought it in '08 or so with 175k on a Duramax diesel and rebuilt Allison tranny because they got tired of the towing bills. After removing all the aftermarket crap, replacing the ignition switch and rebuilding the filterhead I drove it to 390k when I sold it.

 

............I will post updates as needed. Thank you Chevy-SS for sending me enough information to fill in the gaps.

John, glad I could help a little. Looks like you have become the resident expert on this, haha! Dave