Lost Car Key - Any Way To Reprogram Car To Avoid Theft?

[Number_35]

A friend lost some keys yesterday, including keys to both vehicles.

He has a 2nd key for each vehicle, but is worried about someone finding the lost keys (which might be in the snow not far away), and pressing the alarm button to find out which vehicles the keys belong with. It's not an issue if the keys are across town, but he doesn't know whereabouts he lost them.

Presumably a locksmith can rework the locks (door, trunk, and ignition) on each vehicle such that the original key will not work in it.

What about the remote functions of the lost key? Can the dealer rework the security system such that the lost key fob cannot unlock the doors?

The vehicles are a 2012 Chevy Sonic and a 2016 Dodge Grand Caravan.

Thanks, input appreciated. I wish I knew more about this stuff.

 

[TheOilWizard]

Can the dealer rework the security system such that the lost key fob cannot unlock the doors?

Yes, absolutely. With my Ford (and presumably all modern vehicles) they are able to see all keys and remove any that are unused/lost/stolen, etc.

 

[dishdude]

Good opportunities to have spares made and the old key and fob removed from the vehicle's memory. I wouldn't bother rekeying the locks, at least with the fob and transponder out of the systems they can't start the car or use the panic functions.

 

[michaelluscher]

This is 100% doable, by a competent locksmith
The Dodge being marginally easier/cheaper (at least with the tools I have)
Only catch is, at least with the GM, you'll have to program two working keys when doing AKL
The Mopar product I've gotten away with only one in the system (maximum of 8)
Fobiks are dirt cheap, even if he doesn't have the emergency keys cut, I'd have two spares made up and lock one in the drawer at home

The cheap no name Fobiks work on the Mopar, but I've been burned twice by non OEM keys with the GMs
Spring for a new OEM GM part, or a Strattec key will also work
Some eBay sellers will cut by picture, or you can go get the keycode out of the dealer (with proof of ownership)

 

[nthach]

On the Toyota side of things, any two-way scan tool or (GTS) Techstream can delete keys or wipe the immobilizer unit clean. IIRC, Toyota wants the immobilizer unit reseeded with a new seed value if wiped clean. That you need to be a dealer tech or a credentialed locksmith.

 

[andrew_j]

On VW all keys get needs to be present to working with a reprogram. So a lost key would no longer function.

 

[Number_35]

Thanks, all. I've passed this information on to my friend, and will report back on how this works out for him.

It was extraneous to my original question, but there was also a house key on the key ring with the car keys. Yesterday we replaced the lock on the front door, so at least they had peace of mind about that.

 

[andrew_j]

I would have faith in humanity and not worry about it personally.

 

[Number_35]

I would have faith in humanity and not worry about it personally.

Indeed, generally these things work out. I have War Amps tags on my keys, have lost them, and have had them returned by courier. (I don't know if you have this in the States, but here, if you find keys with a War Amps tag, you drop them in mail. They are returned, free of charge, to the owner.)

However, one point I didn't mention - both people (husband and wife) thought they heard their car chirp in the middle of the night, making them suspect someone had found the keys nearby, and was walking around checking to see which car they belonged to.

Fortunately, the car was in the garage, and the van was boxed in by a snowdrift.

 

[andrew_j]

I found a pair of keys in a lot, clicked it and unlocked related car opened door and set keys into car leaving unlocked.

 

[Number_35]

I was over there yesterday evening. The van is parked for the winter. We cleared the snow off the good, and disconnected the -ve battery terminal.

A determined thief could still enter (using the physical key hidden in the fob), pop the hood, reinstall the cable, and steal the van, but I thought doing this was a good first step.

I've suggested we pull a critical fuse or relay until the security issue is resolved. May do that tomorrow.

*******

The owner phoned earlier today. He had checked into getting the existing key reflashed or recoded (I'm not sure of the correct terminology) and considered the price excessive.

He's suggested getting a used ignition cylinder and key from a wrecker, and replacing the cylinder in his van.

Would this work? I'm skeptical, assuming the key is associated with the VIN (and therefore the ECU or BCM).

Even if it works, he would still want a 2nd key, so would have to get his existing key coded or programmed to match the replacement - and get the door and hatch lock rekeyed also. It gets messy.

Thoughts? Thank you again in advance.

 

[xmanjeff]

i had one in my set that stopped working , i bought one online and went thru the prompts in the owners manual ,i believe i read that it puts a new code in on the relearn that an old key that doesnt go through the relearn wont work

 

[thescreensavers]

I would purchase another key, and get the car reprogrammed. 1. to clear all keys and 2. To program the two new keys

 

[Number_35]

Update:

1. The couple whose keys were lost are both almost certain that they heard both the van's alarm and car's unlocking "chirp" in the middle of the first night after the keys were lost.

The car (2012 Chevy Sonic) was in a locked garage, and the van (2016 Dodge Grand Caravan) was parked in the back for the winter, blocked by a ridge of snow, so neither vehicle was stolen.

Given that the keys were not left in the mailbox or otherwise returned, it's reasonable to assume the keys were found by someone with bad intentions.

2. A trusted local locksmith said they were unable to reprogram the remaining key for the van. I'm not sure about the car.

3. The Dodge dealer wants C$300 for a new key, plus C$69 to program it. I don't know whether the dealer can reprogram the remaining original key.

4. Reprogramming keys wouldn't stop the original key from being used to open the vehicle.

5. My suggestion at this point is to see whether our mandatory public auto insurance will cover this situation. I think that would involve rekeying the locks on both vehicles, plus programming the new keys. It gets expensive quickly. Their deductible is C$500, but that's starting to sound like the cheapest way forward.

 

[Fordiesel69]

4 - that is incorrect information.

Emphasis on "skilled" locksmith. Both GM and Stellantis can have their modules wiped clean, and you can re-program new keys.

You can also have a locksmith clone existing key in some cases to a new one that is blank. The module will have one ESN that works for either key. This is not ideal as should be done as a last resort.

Its 2025 now. No you cannot just leave it. You must re-program new keys. And erase the old ones.

 

[Nukeman7]

Update:
......
4. Reprogramming keys wouldn't stop the original key from being used to open the vehicle.

4 - that is incorrect information.

Emphasis on "skilled" locksmith. Both GM and Stellantis can have their modules wiped clean, and you can re-program new keys.

You can also have a locksmith clone existing key in some cases to a new one that is blank. The module will have one ESN that works for either key. This is not ideal as should be done as a last resort.

Its 2025 now. No you cannot just leave it. You must re-program new keys. And erase the old ones.

@Fordiesel69, I think you are misunderstanding what Number_35 meant. He is saying the lost cut metal key(s) will still be able to physically unlock the exterior door and trunk lock mechanisms unless the lock cylinder tumblers are changed.

 

[Number_35]

4 - that is incorrect information.

Emphasis on "skilled" locksmith. Both GM and Stellantis can have their modules wiped clean, and you can re-program new keys.

You can also have a locksmith clone existing key in some cases to a new one that is blank. The module will have one ESN that works for either key. This is not ideal as should be done as a last resort.

Its 2025 now. No you cannot just leave it. You must re-program new keys. And erase the old ones.

I worded 4 poorly - @Nukeman7 wrote what I meant.

 

[Number_35]

It's resolved now - a mobile locksmith rekeyed the locks on the Sonic (preventing the lost key from physically opening the door or turning the ignition), reworked the original key to work in the rekeyed ignition and door lock, cut a new 2nd key, and reflashed the electronics. (Sorry if my terminology is not right.)

All this for C$193.

 

[Donald]

I would worry more about getting a second key than the lost keys. With some cars you can program a third if you have two working keys without any scanner or other tools.

Ford vehicles can have keys programmed with Forscan.