Key won't turn in ignition on a 2003 Trailblazer

ignition keylock cylinder broken or could have the wrong ignition key.

Most likely it's the ignition switch

1. Close all doors
2. Insert key into ignition
3. Hold down the power UNLOCK button on the driver's door panel, continue to hold down
until instructed to release in step 9.
4. Perform steps 5 through 8 in a fairly rapid succession.
5. Turn the ignition to the ON position (as far as you can go without starting the engine.)
6. Turn the ignition to the OFF position.
7. Turn the ignition to the ON position (as far as you can go without starting the engine.)
8. Turn the ignition to the OFF position.
9. Release the power UNLOCK button on the door panel. The vehicle should respond by
door locks locking and unlocking automatically. (If locks do not cycle after you let go,
not before you let go of the unlock button, then the vehicle has not entered programming
mode and you must start procedure over. Remove key from ignition, open drivers door
and return to step 1 ). If the locks do cycle automatically then proceed to step 10.
10. Hold down the LOCK and UNLOCK buttons on the remote until the doors lock and
unlock. This may take up to 30 seconds.
11. Repeat step 10 NOW for each additional remote. (Including any existing remotes).
12. Turn the ignition to the ON position to exit the programming mode.
13. Test remote(s).

I have a 2004 impala that did the same thing..the ignition switch needs to be replaced

you most likely have a bad key switch cylinder assembly. you can try to spray wd40 solvent into the switch before you have the switch replaced,but sometimes it's a switch replacement that repairs the problem. have you inspected your ignition key to look for damage to the key itself? try a spare key to make sure it's the key,and not the key switch. you can also try turning the key while turning the steering wheel at the same time to get the key to work.sometimes the switch locks when parked in a bind,such as on a hill,or against a curb and so on. try this 1st before you have the ignition switch replaced. AAA auto club,if you're a member covers part of the replacement costs for a replacement switch also. you may have coverage through a cell phone also.one more thing to try, if you have a tilt steering column,try to reposition the steering wheel to see if you can get the key to turn. remember never force it enough to break your key off into the switch! thank you for choosing fixya.com!

Sounds like you need a new ignition switch, not the one that the key goes into, but the actual ignition switch....it's black and it's located on the bottom of the column. Pretty easy job, and is common to go out.

To remove your key....your year had a hole in the plastic, on the bottom side of the steering column, just below the key......some may have been filled or not done at all. Some have an outline of a hole that can be drilled or cut out. Either way, this is an access hole to the solenoid to remove your key. Press this in and your key will come out.

If you can't get the key out of the ignition, it's probably the ignition switch (where the key goes in) that is bad, not the starter. The starter is on the right side under the exhaust manifold behind the right front wheel. It's not easy to change on those unless you know what you're doing.

1) The steering is locked to one end, and exerting pressure on the ignition. On extreme cases, very hard wiggling of the steering wheel is required while trying to turn the key. 2) The shifter lever is just slightly out of Park or neutral, and it will prevent the ignition from turning. 3) Ignition switch mechanicals are starting to go bad (very rare)

tap the lock cylender with a small hammer it will free up the tumblers and the insert key and its working again.

check the Ignition Starter Switch (tipical on tb)