I have a 2012 GMC Sierra 1500 sl crew cab I tried program...

I have a 2012 GMC Sierra 1500 sl crew cab I tried programming a new key fob and it was unsuccessful now the unlock button on the truck doesnt work and when i put the key in the ignition and turn to on nothing happens no lights com...

I have a 2012 GMC Sierra 1500 sl crew cab I tried programming a new key fob and it was unsuccessful now the unlock button on the truck doesnt work and when i put the key in the ignition and turn to on nothing happens no lights come on and the car wont start Mechanic's Assistant: Can you turn the steering wheel at all? And what about the key? Is it worn or damaged? Yes and no the key is perfect Mechanic's Assistant: Are you fixing your Sierra 1500 yourself? What have you tried so far? I was just trying to program a new key fob and now i dont know what to do i tried disconnecting the battery to see if that would work Mechanic's Assistant: Anything else you want the Mechanic to know before I connect you? No thats it

Automotive Expert
Hi. I'm Daniel, I'll be the mechanic assisting you today. I'm sorry to hear about the issue you have with your GMC. Let's see if we can figure this out and get you back on the road quickly. How did you try to re-program a new key? Do you still have a working "master key" at hand at this point?

It was the Key fob i was programming and it was a process like close all doors insert key in ignition hold down unlock on drivers door turn the key to the on position and of two times release the unlock on drivers doorthats as far as i got because the car didnt unlock and lock itself like it was supposed toBut now when i insert my key in the ignition and turn to on nothing happens and the truck wont startHello?
Automotive Expert
Please do give me a few minutes between replies. Do you still have a "master key" at this point to start the car? What tools and equipment do you have at hand? Are any lights coming on if you turn the ignition on or is nothing happening at all? Did you verify that the battery is still charged correctly?

battery is good yes i have the key but nothing is happeningWhen i put the key in the ignition and turn it nothing happens no lights no cranking nothingUmm pretty fair selection of basic tools
Automotive Expert
Can you see the security light when you try to turn the ignition on? Do you have a capable diagnostic scanner to access the electrical system on your car?

Where is the security lightI dont think the security light is on i dont see any lightno i dont have a scanner
Automotive Expert
Thanks for this info. Unfortunately I won't be able to help you any further with this and provide a simple solution. I will open this question up, hopefully another expert has additional information for you.

Automotive Expert
The only way to program the key fob is with a scan tool. I see that you don't have one so you'll either have to call an automotive locksmith to come out and program it for you or you will have to bring it to a repair shop. If you can get a scan tool, here's the procedure: 1. Install a scan tool. 2. Turn ON the ignition with the engine OFF. 3. With the scan tool, select Body. 4. Select Remote Control Door Lock Receiver (RCDLR). 5. Select Module Setup. 6. Select Program Key Fobs. 7. Select the key fob desired to be programmed. 8. Follow the scan tool on screen instructions. 9. Remove the scan tool. 10. Exit the vehicle. Operate all functions on transmitters to verify correct system operation.

What kind of scan tool

will that make the truck start again?
Automotive Expert
A scan tool that can communicate with the door lock module. There are dozens of scan tools that can do this. You would have to search online for one that fits your budget. The Tech2 is a good one. Yes if you program the key it will allow it to start.

Could you possibly provide me with a link to anywhere i can purchase one?Also I originally had 2 programmed keys that worked with the vehicle and one working key fob and one new unprogrammed key fob. How come my keys ceased to work
Automotive Expert
I don't have a link unfortunately. You would have to search online to see which one fits your budget. They range from $3000 - $20,000 and I don't know how much you want to spend. If the keys quit working then it must have lost it's transponder ID.

Okay another thing i looked up the scan tool you suggested and it says it doesnt support trucks. Also, the unlock and lock button on the drivers door stopped working as well
Automotive Expert
The Tech2 supports all GM vehicles. Im not sure why it said that. You would be able to see what the lock problem is with the scan tool.

Thank you for your time. We took the battery off and charged it over night. put it back in and the truck started. Whew!
Automotive Expert
Awesome! You're very welcome and I'm glad to help!

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