# What is this box for? **URL:** \ **Category:** General Discussion\ **Tags:** sierra-1500, gmc\ **Created:** [April 23, 2022, 11:02pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768 "2022-04-23T23:02:44Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![Meadow](https://avatars.discourse-cdn.com/v4/letter/m/aeb1de/32.png) [@Meadow](https://community.cartalk.com/u/Meadow)\ **Post date:** [April 23, 2022, 11:02pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/1 "2022-04-23T23:02:44Z")
![image](https://global.discourse-cdn.com/cartalk/original/3X/d/a/daccdf456c6b4f7d9da52777502c5b3d72d75ba2.jpeg) Can anyone tell me what this device is and what it does. It blinks a green light constantly. There is a small oval shaped button on its face, but pressing it does not seem to produce a change in the blinking. ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [April 23, 2022, 11:22pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/2 "2022-04-23T23:22:31Z")
Could you make this quiz any easier? Maybe find a logo on the device? Tell us how many wires on it? It looks like it might be a trailer controller but not ljke any I have ever seen. A year on the box OR the truck’s year might help. ---
**Author:** ![shadowfax](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/shadowfax/32/13026_2.png) [@shadowfax](https://community.cartalk.com/u/shadowfax)\ **Post date:** [April 23, 2022, 11:28pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/3 "2022-04-23T23:28:10Z")
Given that you’re posting this now, I’m guessing you recently bought the vehicle? Did you buy it from a used lot that gave you financing? Could well be a tracker, so they can come repossess the car if you miss a payment. ---
**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\ **Post date:** [April 23, 2022, 11:29pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/4 "2022-04-23T23:29:38Z")
Just where is that thing located ? As Mustang said are there any markings or numbers on that thing ? ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [April 23, 2022, 11:31pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/5 "2022-04-23T23:31:09Z")
Looks like an old add-on immobilizer. ![image](https://global.discourse-cdn.com/cartalk/original/3X/9/9/99a2cbfd57c05335ef3cba68522a9a00d93380b0.png) ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [April 24, 2022, 1:08am UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/6 "2022-04-24T01:08:17Z")
My guess is the same as Nevada’s, some sort of security device to prevent a thief from starting the engine. My Corolla came new w/something like that mounted in that same area. But more hidden than that. To prevent thefts from the dealership parking lot. The dealership disabled it when they sold me the car, but didn’t mention anything about it. About 3 years later I accidentally bumped my knee into that gadget, it cracked, and then the car wouldn’t crank. I had to remove it completely to get the Corolla cranking and starting again. ---
**Author:** ![Meadow](https://avatars.discourse-cdn.com/v4/letter/m/aeb1de/32.png) [@Meadow](https://community.cartalk.com/u/Meadow)\ **Post date:** [April 24, 2022, 4:59pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/7 "2022-04-24T16:59:45Z")
Thanks so much for your reply, Mustangman. There are no logos on the plastic casing. There is a small wiring harness on the back with three wires attached. ![image](https://global.discourse-cdn.com/cartalk/original/3X/4/e/4ecbaa345fe664dfde64ed2a73b677a7a389df38.jpeg) I purchased the truck new in 2020. It is a Denali and came with a factory installed trailer controller. ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [April 24, 2022, 5:04pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/8 "2022-04-24T17:04:27Z")
Then I, too, say it is a security device. I’d take it to the dealer and tell them to remove it. ---
**Author:** ![Meadow](https://avatars.discourse-cdn.com/v4/letter/m/aeb1de/32.png) [@Meadow](https://community.cartalk.com/u/Meadow)\ **Post date:** [April 24, 2022, 5:04pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/9 "2022-04-24T17:04:37Z")
I bought the truck new but can’t say for certain when I first started noticing the blinking light. ---
**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\ **Post date:** [April 24, 2022, 5:05pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/10 "2022-04-24T17:05:53Z")
> [@Meadow](#): > > I purchased the truck new in 2020. It is still under warranty I would think so ask the dealer what that thing is. ---
**Author:** ![Meadow](https://avatars.discourse-cdn.com/v4/letter/m/aeb1de/32.png) [@Meadow](https://community.cartalk.com/u/Meadow)\ **Post date:** [April 24, 2022, 5:08pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/11 "2022-04-24T17:08:52Z")
Thanks Volvo. There are no markings or numbers on the plastic casing. It is screwed to the bottom of the driver’s side dash; between the foot rest and the brake pedal. ![image](https://global.discourse-cdn.com/cartalk/original/3X/6/6/6615f2d0cba43a9640f7064493edab9503f6b145.jpeg) ---
**Author:** ![Meadow](https://avatars.discourse-cdn.com/v4/letter/m/aeb1de/32.png) [@Meadow](https://community.cartalk.com/u/Meadow)\ **Post date:** [April 24, 2022, 5:14pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/12 "2022-04-24T17:14:06Z")
Thank you. I will do that. ---
**Author:** ![Purebred](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/purebred/32/46796_2.png) [@Purebred](https://community.cartalk.com/u/Purebred)\ **Post date:** [April 24, 2022, 8:56pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/13 "2022-04-24T20:56:42Z")
Please let us know what it is. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [April 24, 2022, 9:05pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/14 "2022-04-24T21:05:46Z")
The security device should be listed on your invoice as “Additional Dealer Package”. ---
**Author:** ![Meadow](https://avatars.discourse-cdn.com/v4/letter/m/aeb1de/32.png) [@Meadow](https://community.cartalk.com/u/Meadow)\ **Post date:** [April 24, 2022, 9:25pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/15 "2022-04-24T21:25:42Z")
I will. Thanks for your help. ---
**Author:** ![zyemaster](https://avatars.discourse-cdn.com/v4/letter/z/dfb087/32.png) [@zyemaster](https://community.cartalk.com/u/zyemaster)\ **Post date:** [June 16, 2026, 8:07pm UTC](https://community.cartalk.com/t/what-is-this-box-for/183768/16 "2026-06-16T20:07:47Z")
This is a Karr GPS tracker, installed by dealerships to track you and your vehicle to make reposession easier. I would remove it asap as they will sell your location info to anyone that will pay them for it.