BTW..I have the same exact craftsman meter that you have. I have a bunch of them, but the craftsman is old reliable and the one I use the most and have been for a LONG time.
SOLVED! Passlock problems continue. Going on 5 years now...
- Thread starter jmonica
- Start date
So in thinking about the Passlock system and starting to understand how it works... given that the keys don't contain any kind of transponder or resistor, the one and only purpose of the system is to prevent someone from removing the ignition cylinder (like with a slide hammer), or drilling it out it to the point where they can use a screwdriver or something to turn the ignition. Am I right that is the sole purpose of the passlock security system?
Also, it appears the guy who installed the RS ran a wire to the drivers door. Any idea what that could be used for?
Also, it appears the guy who installed the RS ran a wire to the drivers door. Any idea what that could be used for?
This is correct. As soon as the BCM wakes it should put 5 volts on the yellow wire. (nominal, it may vary slightly).
If there is a lower voltage there then something is causing it. Like a resistor to ground (or low reference).
And further, no message from any bypass module can lower this voltage. It HAS to be a circuit path to ground, like through a resistor.
GM figured that if the ignition lock cylinder could turn to START then the person must have the right key.
This system prevents anyone from just jumping the wires at the ignition switch to start the vehicle,,,(hot wiring) because the security system won't let the engine start and run without the ignition lock cylinder turning to START.
The passlock system continues to monitor that sensor voltage as you drive. If it sees the voltage change to a different code the security light goes on and the system is in a state of "Fail-Enable" I believe. In this state I think it will let you turn off the engine and restart so you are able to get back home without being stranded.
Hi. SO after having to take break from this for a few weeks, I am back at it. Between work and my Son and helping a friend clean out a house after his father passed away, there's just been no time to work on it.
My worry has been making the car inoperable for as long as it takes to fix it, once I start tearing into it, so I've also needed to wait until the weather forecast looks decent enough to where I can ride my motorcycle to work should fixing this turn into a multiday nightmare.
So now with all of these things out of the way, I took tomorrow off work to dig into this and hopefully get it sorted once and for all.
I just need to try to wrap my brain back around what's going on and what the awesome Mr. TJBaker57 has told me to do.
I started poking around today and found the PL bypass module. My plan is to remove it and try to restore all of the wiring to original as best I can. I'm really going to miss the remote starter especially in the snow, but that's life.
Going to do some research on the bypass module and try to find the installation instructions. I see at least one wire that was cut that's not connected to anything, that I will likely have to reconnect, assuming it is related.
I'm also really curious as to why the guy had to run a wire to behind the door panel, not that it matters now if I am removing it. I'd love to crack open the module, see what resistor is in there and change it to one that will not be so close the threshold, but I don't trust myself enough to get that right.
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So I found the installation and programing instructions for the bypass module and now I am second guessing removing it for the fear of really messing everything up.
I considered reprogramming it, to match the resistor code of the the vehicle, which is the final step of setting this thing up, but given that the problem I have is intermittent, do you think it makes any sense to even bother with that?
I understand that the the voltage value is on the threshold and so the system is having to relearn, but I don't know why the voltage would fluctuate or how I can prevent it from happening or make it so that it doesn't matter if it fluctuates a little by getting it away from the threshold values. .
My problem is, I think I understand what is happening (Thanks to TJBaker57 and Mooseman), but I don't understand what is causing the problem to come and go or how to correct it, so I am not sure what to do to remedy it and would really love to hear your thoughts if you have the time? Please? Thank You
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Mooseman
Moderator
I would say no, it should not. I am reviewing the thread, reacquainting myself with the particulars. I have some idea for going forward and will post up in a short while tonight.
Do you use that remote start often? Does the vehicle security error ever happen when the remote start is used? (the vehicle would fail to start remotely of course)
Reprogramming might not be bad idea. It would be useful to know more about how the bypass module implements the resistive path to ground. If it has nothing more than a fixed set of resistances inside it then a reprogramming/relearn of the passlock resistor code may not change anything if it simply reselects the same internal resistor it is currently using.
But if it somehow employs some electronic circuitry to reproduce the learned resistive value then there is a possibility that with a relearn it could more closely produce the vehicles own Passlock sensor resistive value.
Before I tried a relearn of the bypass module I would check a few connections.
Trace out the bypass module blue data wire that cuts into the yellow passlock sensor wire. Make absolutely certain this is a solid, clean connection.
Trace out the black ground wire of the bypass module and make absolutely certain the installer connected this to a good solid reliable ground.
Maybe disconnect and check and reconnect the BCM connectors 1 and 2 confirming that the 3 Passlock wire terminals are in good clean order.
There is still something that does not seem right here. When you previously checked the Passlock Data voltage you never saw the initial 5 volts (or close).
Even with the new information about the bypass module this is still unexpected/unexplained. The bypass module resistance should only be applied between the yellow Passlock sensor wire and ground when the remote start is activated to start the engine. And the factory Passlock sensors own resistance across the yellow and ground wires should only be applied after the key is turned to the START position.
So why do we not see the nominal 5 volt Passlock Data signal when neither of these resistances should be actively applied??
Hi. Lately, I have been using the RS anytime I take my car to work which has been once or twice a week. The only reason being so that if the PL system starts acting up, I can sit inside while I wait through the ten minute cycle(s). I haven't had it fail in a while when using the RS, but it can and does occasionally meaning I feel like it would fail whether I use the key to or the RS. The worst part of trying to diagnose this (and dealing with it), is the randomness of it. This last episode on Friday after work, was the first time I happened in about a month. This time I had to sit there for 40 minutes (4 cycles). It's funny, each time I go to turn the key, I cringe before I ask the car gods to please let it start. If not, I put the seat back settle in to sit there for at least 30-40 minutes.
So I think I need to test the voltage at the yellow wire at the BCM as you have explained.
Then check and possibly reconnect all of the wires at the RS and bypass module, check the ground etc., Then recheck the voltage at the yellow wire again.
One thing I haven't mentioned...when I start the car, usually the security light is out and then will go on after a little while (Maybe 10 minutes, but I haven't timed it exactly). Sometimes I will start it and the security light is on steady. I need to keep better track of this and I will. Whether its on or not doesn't seem to affect the starting.
So I feel like with the intermittent nature of this and the voltage fluctuations, that a bad ground could be the possible culprit, but that's just a guess.
I hate problems like this. The fact that it's not re-creatable makes it difficult to diagnose. I think the key to knowing if I have found the problem is checking the voltage at the BCM. The hope is that I check it, check the wiring, and find something that looks suspect, I fix the connection and test and wallah, I then have 5 volts at the yellow wire.
I can't tell you how grateful I am for You sticking with me on this. It's 8:30AM here and 37 degrees. I'm working on it in the driveway so I am going to down a couple of red bulls and dig into it in about an hour when it gets a little warmer. I also have do an oil change on it today.
Thank You TJBaker!
So I think I need to test the voltage at the yellow wire at the BCM as you have explained.
Then check and possibly reconnect all of the wires at the RS and bypass module, check the ground etc., Then recheck the voltage at the yellow wire again.
One thing I haven't mentioned...when I start the car, usually the security light is out and then will go on after a little while (Maybe 10 minutes, but I haven't timed it exactly). Sometimes I will start it and the security light is on steady. I need to keep better track of this and I will. Whether its on or not doesn't seem to affect the starting.
So I feel like with the intermittent nature of this and the voltage fluctuations, that a bad ground could be the possible culprit, but that's just a guess.
I hate problems like this. The fact that it's not re-creatable makes it difficult to diagnose. I think the key to knowing if I have found the problem is checking the voltage at the BCM. The hope is that I check it, check the wiring, and find something that looks suspect, I fix the connection and test and wallah, I then have 5 volts at the yellow wire.
I can't tell you how grateful I am for You sticking with me on this. It's 8:30AM here and 37 degrees. I'm working on it in the driveway so I am going to down a couple of red bulls and dig into it in about an hour when it gets a little warmer. I also have do an oil change on it today.
Thank You TJBaker!
Thanks Moose. It didn't make sense to me either, just trying to figure out what's causing the voltage fluctuations. I feel like it's almost got to be bad / loose wiring or a ground at the Bypass module. Thanks Again!
Mooseman
Moderator
When I had the Saab, my secondary key didn't have a working chip in it (yes chip, it's a Passkey) and whenever I used it, the security light would flash and keep flashing while driving. It was tuned and had the VATS turned off in the PCM so it ignored the 'do not start' command.
I still recommend just getting the damned thing tuned and getting over with it.
I still recommend just getting the damned thing tuned and getting over with it.
Yes, this is another clue pointing to poor connection(s). Even after the truck has started the BCM continues to monitor that Passlock Data Voltage. If it fluctuates outside of the thresholds for the Passlock code it has learned then it will light the security light and set a code. In these cases the Passlock may enter a "fail-enable" state that will allow a restart even with that "bad" code so you are not stranded in a parking lot or what have you.
Not only a ground but that bypass module blue wire to the passlock sensor yellow wire. A poor connection there would cause the Passlock Data voltage to drift higher same as a poor ground will.
One thing that surprised me was the bypass module does not apparently use the same low reference ground as the passlock sensor does for placing a resistance to ground on the yellow BCM/Passlock wire.
This may open up the possibility of a different ground potential applied to the yellow wire when the bypass module is active vs when the passlock sensor is active. Did I state that clearly? So when the bypass module places the resistance in the circuit from yellow to ground it is not using the same ground (or low reference) as the passlock sensor does. Often there are resistive diferences between ground points.
Not knowing how the bypass module functions internally it is difficult to say what to expect here. This much is certain, only one of the resistances, Passlock sensor OR bypass module, can be applied at a time. It cannot work with both active at the same time. With this in mind I would expect the bypass module to disengage completely when not active so then we should be seeing the full voltage in the Passlock Data signal before starting the engine.
I would proceed in this order:
Disconnect the harnesses from the Bypass module and recheck for the 5 volt Passlock data signal at key RUN position.
If the nominal 5 volt signal is still not there then disconnect the Passlock sensor at the harness on the ignition lock housing and retest for the nominal 5 volt signal.
We need to assure the 5 volt signal is there before the engine is started (or the key has been turned to START).
Recheck all associated wiring, ground points, splices, etc.
Consider running the bypass module reprogramming sequence. Reading how this procedure is done tells me that the device reads the Passlock Data signal voltage during the relearn and calculates the required resistance to produce the same voltage seen during the learn procedure.
If the module is not simply using fixed resistors inside and
for whatever reason the voltage read during the learn was very close to a threshold value it is possible that the bypass module will learn and recreate that value from then on. In this case it would be nice to have a Passlock voltage that is not near a threshold value during the learn procedure.
If the bypass module uses fixed resistances then the best hope would be that we find a poor connection somewhere that is causing the Passlock Data voltage to be too close to a threshold value.
There may be one other issue:
Recently, issues with an IPC Draining a Battery due to having a Weird Phenomena occurring where the Non-Lead Solder causes "Tin Whiskers" to Grow and propagate all over the underside of the IPC Logic Board. If that situation was happening here... perhaps replacing the IPC with a Used one for a "Test Run" for a temporary comparison might reveal this as the Hidden Cause and Origin of the Problem:
THIS is what Non-Lead "Silver Migration" Looks Like:
Recently, issues with an IPC Draining a Battery due to having a Weird Phenomena occurring where the Non-Lead Solder causes "Tin Whiskers" to Grow and propagate all over the underside of the IPC Logic Board. If that situation was happening here... perhaps replacing the IPC with a Used one for a "Test Run" for a temporary comparison might reveal this as the Hidden Cause and Origin of the Problem:
THIS is what Non-Lead "Silver Migration" Looks Like:
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Hey Guys. I wanted to apologize for just going radio silent after all of the time and effort spent trying to help me with this problem. Soon after my last post I got into a fairly serious motorcycle accident. I'm just recently able to use my hand to type on my phone with. I feel bad that I didn't reply after all of the help.
One of my last posts I had posted a photo of the remote starter bypass module that's located under the steering column. In addition to the passlock problems, I had a steady on security light, most of the time.
It's by some act of the cars gods that once I took the photo and reinstalled (plugged in) the module, the next day I had no more sec. light and knock on wood, I haven't had the no start problem ever since.
I'm assuming a loose connection because I just removed and reinstalled it.
I'm very fortunate because my motorcycle was my backup means of transportation to work, now that it's unridable, I'd be screwed without the Envoy. Which is still on its last leg but running thankfully.
So I just wanted to say I'm sorry and once again say thank you so much for all of your help.
I hope you all have a Merry Christmas and enjoy the holidays.
One of my last posts I had posted a photo of the remote starter bypass module that's located under the steering column. In addition to the passlock problems, I had a steady on security light, most of the time.
It's by some act of the cars gods that once I took the photo and reinstalled (plugged in) the module, the next day I had no more sec. light and knock on wood, I haven't had the no start problem ever since.
I'm assuming a loose connection because I just removed and reinstalled it.
I'm very fortunate because my motorcycle was my backup means of transportation to work, now that it's unridable, I'd be screwed without the Envoy. Which is still on its last leg but running thankfully.
So I just wanted to say I'm sorry and once again say thank you so much for all of your help.
I hope you all have a Merry Christmas and enjoy the holidays.
Hope you heal up OK. I haven't ridden since 1982. Had a Norton Commando 750 Interstate and a Honda CB750 K4. Crossed the continent a few times.
A loose/poor connection fits the issue we were seeing. Lets hope it stays good for you.
Thanks for your well wishes. I've done a couple of cross country trips on a different bike. One when I was younger and there were no helmet laws. I left with no rain gear, no tools, no real planning. I do think I had a map and a Walkman. Oh to be young and carefree... or just young and dumb.
It's funny, only one single thought went through my head as I was crashing.
The thought was "Wow, I can't believe I'm really crashing".
I think that was the moment my brain figured out I wasn't going to somehow avoid it and I was definitely going down, or in this case, up and over, then down. That's all I remember.
Did you ever go down on your bike?
Thanks again.
Only once at about 45-50 mph a Honda CB450 that slid out from under me on a circular freeway onramp in California, 1975. Busted a turn signal and scraped a muffler is all that happened there.
Nothing else worthy of mention.
1979 or 1980. Badlands, South Dakota. Had maps, no real plans, slept under highway bridges or camped in National Parks etc.
Mooseman
Moderator
Well, you never know. It could come back and rear its ugly head again and we never really found the root cause so it wasn't really "solved".
Definition:
But it's been hanging for 5 years so why the hell not?
SOLVED!
Great pic! Even though I don't know you, that pics brings back a flood of memories for me.
We lived in Ventura California in '75
It doesn't look like you had in all of your protective safety gear. 😀 I'm kidding!
It was a different time for sure. I may sound old but it was a better time. You could do things like pile into the back of a pickup truck and not get hassled.
Anyway thank You for sharing.
Ahh nice. I've spent a lot of time and dated a few girls from Simi over the years. My sister currently lives there. I'm currently stuck living in Jersey. I sure do miss that Cali weather!
Have a Merry Christmas!
