# Disable remote lock and unlock



## Bones (Jun 30, 2015)

So twice so far this year someone has broken in to my Cruze. There is no damage to the windows or doors, and judging by the fact that the dirt isn't even smudged (i don't wash my car often) it appears that whoever has been doing this has a way to unlock the car remotely. Seems logical right?

Well, last night was the second time this happened, and I doubt it was the same person as the March 25th incident because nothing was stolen this time, just all the switches messed with, and flashers turned one. Also, this time it happened in a completely different part of town, and it would seem too coincidental for it to be the same person going the same places I do. 

Anyhow, I spoke to the GM corporate number, said they've never heard of it happening before, and recommended i speak to a GM certified mechanic. So I called up 3 dealerships, only one has returned my call, and the best the one could offer was attempting to recode the frequency on the keyfob/receiver so that i'll be on a different frequency than these intruders for a cost of $100USD. He also stated that my idea of severing all power to the power locks wouldn't be possible.

So now to my question, despite what the one mechanic said (it was better than the guy i got before, he told me to get a security camera so I asked for someone else) is it possible to install a killswitch (preferably the type with a removable key) in the data lines going from the key fob receiver, to the locks themselves? I'm told that these signals are sent through the BCM before it goes to the locks, and i have no idea how that will effect this plan. 

Basically, is there a way I can make this work without having to just install a battery disconnect(more convenient for my wife than taking the leads of the battery every time she parks the car) or are there any other possible solutions? At this point I'm open to suggestion, but I really don't want to spend $100USD just so the thief/vandal will lose access till he figures out the new frequency.

I have one other theory on this, and that is that the car might be randomly unlocking itself due to some electrical problem that shows no other symptoms and the people getting in to my car just happen to be the kind of jerks who just go around checking for unlocked cars.


Any thoughts?


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## ChevyGuy (Dec 13, 2014)

Bones said:


> There is no damage to the windows or doors, and judging by the fact that the dirt isn't even smudged (i don't wash my car often) it appears that whoever has been doing this has a way to unlock the car remotely. Seems logical right?


Check the keylock in the driver's door. Make sure that hasn't been screwdrivered. 




Bones said:


> Anyhow, I spoke to the GM corporate number, said they've never heard of it happening before,


I've seen some vague reports here and there - nothing Cruze specific but it does seem to be possible. It doesn't seem to be widespread - yet. But I'd expect them to go stealing more valuable keyless ignition cars rather than fooling around with a Cruze. If it works like I think it does, you can minimize your exposure by not using the remote to lock the car. I find depressing the driver's door plunger as I get out works fine. Locking the driver's door locks all doors. But that same trick doesn't work so well on other doors.




Bones said:


> So I called up 3 dealerships, only one has returned my call, and the best the one could offer was attempting to recode the frequency on the keyfob/receiver so that i'll be on a different frequency than these intruders for a cost of $100USD.


Hmmm, I'm not sure how they'd change the frequency. I think there's only one frequency for any given county. What they could do is clear all the keys programmed to the car to make sure that there isn't a "spare" fob roaming around out there. Perhaps added by a malicious valet.




Bones said:


> He also stated that my idea of severing all power to the power locks wouldn't be possible.


True. The Cruze is a computer on wheels. Much of the stuff is handled via a databus and remote modules. Even simple things like the door locks and dome light circuit. Killing power to a module is going to create more problems. (The BCM will throw a code if it's not able to talk to a module.) Frankly, the camera idea isn't a bad one. If you can get pictures of the guy, there's a good chance he's known to the police and they can go and find out what's going on. That's available in some dashcams and dashcams are not a bad idea.




Bones said:


> Basically, is there a way I can make this work without having to just install a battery disconnect(more convenient for my wife than taking the leads of the battery every time she parks the car) or are there any other possible solutions?


I'll have to check what gets killed by the "battery saver" circuit. Because I'd be tempted to add a kill switch in series with that relay. I think there's a better chance that won't upset the system. (Although it's still a chance since the BCM wouldn't be commanding the shutdown.)




Bones said:


> I have one other theory on this, and that is that the car might be randomly unlocking itself due to some electrical problem that shows no other symptoms and the people getting in to my car just happen to be the kind of jerks who just go around checking for unlocked cars.


Entirely possible. The remote has quite a range. I can lock my car through two floors of cement and rebar. If the unlock button gets bumped, that could do it. I'd suggest taking steps to secure the keyfob from accidental key presses. There used to be a problem with uncommanded trunk release that was traced to the fob. GM came out with a change that required either two presses or a press and hold to release the trunk. But who's to say you couldn't have the same issue with the unlock? (Accidental button press) I'd also suggest not unlocking the car until you're right there at the door so you can verify if the car was locked before you arrived. If you're using the remote to unlock from 10 feet away, you have no clue if the car was already unlocked - so you have no "warning" that your car is unlocking itself.


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## Bones (Jun 30, 2015)

ChevyGuy said:


> Check the keylock in the driver's door. Make sure that hasn't been screwdrivered.


First thing I checked both times. Definately not the case here. 



ChevyGuy said:


> I've seen some vague reports here and there - nothing Cruze specific but it does seem to be possible. It doesn't seem to be widespread - yet. But I'd expect them to go stealing more valuable keyless ignition cars rather than fooling around with a Cruze. If it works like I think it does, you can minimize your exposure by not using the remote to lock the car. I find depressing the driver's door plunger as I get out works fine. Locking the driver's door locks all doors. But that same trick doesn't work so well on other doors.


As for using the plunger, I was under the impression that it didn't engage the theft deterrent system, atleast that's how it worked on my Pontiac unless certain options were set in the DIC and I have yet to find that option in the Cruze, but I'll give it a shot. Not that the theft deterrent system has done any good for me anyways. Hasn't gone off either time. 



ChevyGuy said:


> Hmmm, I'm not sure how they'd change the frequency. I think there's only one frequency for any given county. What they could do is clear all the keys programmed to the car to make sure that there isn't a "spare" fob roaming around out there. Perhaps added by a malicious valet.


Supposedly they did that when I got the car. it was sold to me with only one key, and they claimed when I got a second key made that those would be the only two keys that would function. Guess i'll have to double check; guess that's what I get for trusting a dealership. As for the valet theory, since getting this car, the only people who've had access to the 2 keys I have are myself and my wife. I've honestly never been anywhere with valet parking except one hotel in San Antonio, but that was with my Grand Prix and ended in a twenty minute argument where the valet finally let me park my car myself. (I get belligerent about my seat and mirrors being moved. I really need to work on that.)





ChevyGuy said:


> True. The Cruze is a computer on wheels. Much of the stuff is handled via a databus and remote modules. Even simple things like the door locks and dome light circuit. Killing power to a module is going to create more problems. (The BCM will throw a code if it's not able to talk to a module.) Frankly, the camera idea isn't a bad one. If you can get pictures of the guy, there's a good chance he's known to the police and they can go and find out what's going on. That's available in some dashcams and dashcams are not a bad idea.


I had the same thought about the throwing codes part, which is why I got the kill switch idea. Figured I'd lock the car, have the switch installed outside the cab, kill it after i got out, activate it back before unlocking the car, and hopefully have the startup system check resolve any issues it might have decided it had, but I honestly have no idea how that would work in real life. as for the camera, I could try it, but the prints they got off my car and the 12 others cars they hit on 3-25-16 still haven't turned up any results, so I don't have a lot of faith in the Police here actually giving it much attention, not to mention trying to power a dashcam over night without it killing my battery. I'll check to see if anyone online has come up with a good way.



ChevyGuy said:


> I'll have to check what gets killed by the "battery saver" circuit. Because I'd be tempted to add a kill switch in series with that relay. I think there's a better chance that won't upset the system. (Although it's still a chance since the BCM wouldn't be commanding the shutdown.)


if you've got any good schematics on the circuit I'd love to have a look at them.




ChevyGuy said:


> Entirely possible. The remote has quite a range. I can lock my car through two floors of cement and rebar. If the unlock button gets bumped, that could do it. I'd suggest taking steps to secure the keyfob from accidental key presses. There used to be a problem with uncommanded trunk release that was traced to the fob. GM came out with a change that required either two presses or a press and hold to release the trunk. But who's to say you couldn't have the same issue with the unlock? (Accidental button press) I'd also suggest not unlocking the car until you're right there at the door so you can verify if the car was locked before you arrived. If you're using the remote to unlock from 10 feet away, you have no clue if the car was already unlocked - so you have no "warning" that your car is unlocking itself.


I typically use the key in the hole unless it's pouring down rain. It's an old habit from my Caprice that carried over in to the Grand Prix. Their Keyfobs were bigger than I liked keeping in my pocket. Sadly the Cruze's is part of the key, so i can ditch it in a junk drawer like i have my previous ones. As for the accidental button presses, I know that wasn't the case at home because once i get out of the car at home the key goes straight to a hook on the wall in the house and it's definitely not getting pressed there. It sits alone on a hook with my house key on another hook next to it, both without rings. I'm a bit picky on what goes in my pockets. I've yet to find it unlocked when I got to the car except on the occasions when things were obviously gone through by someone. I did have a random trunk pop 3 months ago, but that was about the extent of unattended unlocking without some obvious intrusion going on.


I appreciate the feed back, but at this point i'm still leaning towards isolating the battery from the whole system given the whole BCM issue, unless your battery saver idea looks like it will work. Not having a clock displaying the wrong time would be preferable.


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## ChevyGuy (Dec 13, 2014)

Bones said:


> I typically use the key in the hole unless it's pouring down rain.


You're using the physical key in the lock and not setting off the alarm? That doesn't sound right.


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## Bones (Jun 30, 2015)

ChevyGuy said:


> You're using the physical key in the lock and not setting off the alarm? That doesn't sound right.


is it supposed to set it off? Crap, this is starting to sound like yet another issue that this car has that GM will deny is an issue.

Meanwhile, setting off the alarm when using the key sounds like a major design flaw to me.


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## ChevyGuy (Dec 13, 2014)

I forgot, there's another way to unlock the car - OnStar. And they have an app that will do it (via OnStar). You might want to check the status of that system and see who might still have access to the car. I do remember threads about how to disable/unplug the OnStar.

BTW what year do you have? And does it have keyless ignition (push button start) or the keyless entry (push button on door handles)?


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## ChevyGuy (Dec 13, 2014)

Bones said:


> as for the camera, I could try it, but the prints they got off my car and the 12 others cars they hit on 3-25-16 still haven't turned up any results, so I don't have a lot of faith in the Police here actually giving it much attention,


The problem with fingerprints is it has to be in the system and they have to run them. The nice thing about a photo is if it's shown around the station someone is likely to go, "oh, him".


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## Bones (Jun 30, 2015)

@ChevyGuy Good point made on the fingerprints, Considering the dash cam idea. Car is a 2013 LT, and the Onstar subscription isn't currently active, checked that out of paranoia when I bought the car. First time having a vehicle with onstar, and I hate that button on the mirror with a passion. 

Just got done doing some checking about your comment on reply #4, apparently fuse 51 has been out since I bought the car, so for all I know, the alarm has been going off the whole time, just silently. I've had the car since the October before last, and somehow managed not to notice. Amazed I passed inspection.


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## Snipesy (Dec 7, 2015)

Some of the models have the key less entry.

It's insanely unsafe. You can unlock a car sitting outside while your key is hanging on the coat hanger in your house or workplace. You can buy the devices from a few places, or even make your own if you know what you are doing.

IF someone is getting in your car. This is how they are doing it. Spoofing the key itself is insanely hard to do. Anyone who can figure it out is not going to be wasting their time being a thief.


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## au201 (May 18, 2013)

Bones said:


> is it supposed to set it off? Crap, this is starting to sound like yet another issue that this car has that GM will deny is an issue.
> 
> Meanwhile, setting off the alarm when using the key sounds like a major design flaw to me.


If the car was locked with the FOB, then unlocking with they key would set the alarm off. However, when you lock with the key manually, you're not arming alarm system at all. 


Sent from AutoGuide.com Free App


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## Chris Tobin (Feb 23, 2016)

From your description of buying the car used with only one key/remote, I would venture a guess that the original owner or someone once associated with the original owner still has a key, saw the car, recognized it and gave the key a try... Seems plausible to me anyhow.


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## Bones (Jun 30, 2015)

I thought the same, but it seemed slightly unlikely to me because I bought it over 100 miles away from where I live. Maybe by coincidence they happen to go the exact same places I do, but it seems like a stretch. Also, my house, where the first incident happened is really out of the way from anywhere, and was just one stop on a 13 (that I know of) car burglary spree. Could be plausible on the second incident i guess, but still seems like a stretch to me. 

Then again, this wouldn't be the first time that a dealership claimed something to me (like them saying there were no other keys) and they turned out to be full of it.


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## ChevyGuy (Dec 13, 2014)

Bones said:


> Meanwhile, setting off the alarm when using the key sounds like a major design flaw to me.


When you use your fob, the car knows it's "you". When you use the key to unlock the door, it only knows that the door has been unlocked. It doesn't know who/why. As far as I'm aware, the key is a backup for a failed battery. 

Just to add - when you walk up to your car, in addition to verifying that it's locked, you might want to verify that the red light in the middle of the dash is flashing. That shows the alarm is armed.




Snipesy said:


> Some of the models have the key less entry.
> It's insanely unsafe. You can unlock a car sitting outside while your key is hanging on the coat hanger in your house or workplace. You can buy the devices from a few places, or even make your own if you know what you are doing.


Some might be that bad, but I don't think GM's is. You want to give specifics?


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