Have misplaced the keys to my locked 2004 YukonXL and need to open a door.

Possible causes

Faulty Brake Pressure Modulator Valve Assembly

Brake Pressure Modulator Valve Assembly harness is open or shorted

Brake Pressure Modulator Valve Assembly circuit poor electrical connection

door lock silinoid is bad or needs lube

Your door lock mechanism is wire not rods. That's why door won't open. Need to get power somehow. Look under car and see of you can reach up to the hood latch and release mechanism to open hood. If so open hood and hook up a jumper pack. This should allow you to unlock door.

If it is cold enough the mechanism could be frozen. If not the actuator is gone and will need to be replaced.

The dealer can make you a new key. A valet key is limited, but should start the car unless it is missing a chip. It will not open the glove box (if there is a lock) or trunk.

If it's only the drive's side door that's doing it, it's for safety purposes so you don't lock your keys in the car. close the door and use your remote to lock or your keys if you don't have your remote. If you already knew this then the lock switch may be faulty.

go on ebay to by the key and then get it cut at like target or walmart...

once you get the new key...

1-insert and remove key from ignition two times

2-close and open driver door two times

3-insert and remove key once from ign.

4-close and open drvr door twice

5-insert key into ign.,then close driver door

6-turn key to on (not start) then off, twice this is rewrite mode

7-remove key from ignition,the door locks should cycle twice.if not start over.it may take a few tries.

8-press lock/unlock together and hold for a second

9-release,and press lock on remote,the door locks will cycle confirming program.continue to do other remotes you have,steps 8 and 9.if only one in possession,you are done. To end mode open door or insert key into ignition.

You'll need to follow the steps with no more than a 1-2 second delay between each step.. hope it works

IS THE BATTERY DEAD? HOW LONG HAS CAR BEEN LOCKED UP? IF THE VALET KEY WILL NO LONGER OPEN THE DOOR YOU HAVE LITTLE CHOICE BUT TO TOW IT TO DEALER TO HAVE KEY CUT & PROGRAMMED

frist check your wires and make shore you have power. if your lock still dont work its the power lock motor in that door ok . have a nice day

The driver's side door lock button is designed not to lock from the inside unless the handle is pulled, or the power switch is used. This serves as a reminder to not lock your keys inside.

If you are inside, and push down on the button (not the switch) hard enough to lock it, you've probably damaged it.