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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29520
Experience:  GM Grand Master Technician 2007. 14 years experience.
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2005 chevy impala: a brand new ignition switch and lock cylinder

Customer Question

I have installed a brand new ignition switch and lock cylinder with key on my 2005 chevy impala. after completing the installation i turn the key in the off position and now the vehicle does not recognize that the key is in the ignition nor will the key turn. What happened and how can i fix this issue?
Submitted: 5 years ago.
Category: Chevy
Expert:  GM Tech (Cam) replied 5 years ago.

GM Tech (Cam) :

Hello, I'm Cam. Please include all the details about your issue so I can accurately advise you. I cannot see your vehicle so please be detailed.

GM Tech (Cam) :

YOu will need to do this relearn.

GM Tech (Cam) :

Turn the key on, with the engine OFF.Try to start the engine, then release the key to ON, Engine will not start. Watch the security telltale, after about 10 mins, it will turn OFF.
Turn OFF the ignition, and wait 5 seconds.
Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes. You must turn the ignition OFF before attempting to start the vehicle.

Start the engine .

Customer : i
GM Tech (Cam) :


Customer : I cannot turn the key either way... the new ignition is acting as if it is locked. I believe the problem might have been caused when I accidentally turn the key in the off position before connecting the ignition switch wires. How do I unlock the ignition now so that I can begin the re learning process.... h
GM Tech (Cam) :

The key not turning is only the tumblers, did you key the new cylinder and stake the cover on the top of the cylinder prior to installing it?

Customer : the cylinder came with key already.... all I did was unpack and install all new parts....
GM Tech (Cam) :

OK then there is a problem with the new cylinder.

GM Tech (Cam) :

To let you know there is nothing electronic that prevents the key fron turning on.

Customer : It has to be something else because the install process required that the key be in the on position when re installing. And that was not the case when I installed it. I mistakenly turn they key and now it is locked...
GM Tech (Cam) :

If the key cylinder is seated fully and the key does not turn it then it is nothing else but a bad cylinder.

GM Tech (Cam) :

just because it is new does not mean it is with out faults.

Customer : The key was turning just fine prior to the install...
GM Tech (Cam) :

But that was where it was not interacting with the switch inside the housing.

GM Tech (Cam) :

IS the cable loose then in the back?

Customer : Now?nope, everything is nice and tyight in its place... to make it a little clearer, if you lock a cylinder while it is removed tyhen ot will lock and that is what happened. my question is how do i unock it now?
GM Tech (Cam) :

You will need to drill a hole in the housing to press the button to get it out now.

Customer : I want to remove it from the new housing then unlock it...
GM Tech (Cam) :

yes, unless it is turning, you need drill a hole.

GM Tech (Cam) :

Drill a 9/32 hole as indicated.

GM Tech (Cam) :

Full Size Image

Customer : Wow damage the new parts i just installed. Now way to unlock it otherwise?
GM Tech (Cam) :

Nope, but a small hole in that place will not damage the assembly, only allow you to remove it and start over.

GM Tech (Cam) :
Use the following procedure if the ignition switch lock cylinder is seized or won't rotate:

12.1 Protect the immediate work area with suitable material such as clean shop towels or a clean fender cover.

12.2 Locate the surface for the release button (2) for the ignition switch lock cylinder on the plastic ignition switch housing. Center punch a location (1) on the rib approximately 3/8 inch reward, toward the key entry end, from the cylinder release button.

12.3 Carefully drill a pilot hole through the plastic housing with a 1/8-inch drill bit.

12.4 Using a 9/32-inch drill bit, carefully drill a larger hole at the pilot location, and slightly into the surface of the ignition switch lock cylinder, to break the release button retaining spring.

12.5 Remove portions of the broken spring from the hole using a small suitable tool.

12.6 Grasp the ignition switch lock cylinder and remove the cylinder from the switch housing.

12.7 Remove any plastic flash from the drilling operation, and using compressed air blow out the ignition switch assembly.
Customer : Gotcha, ok then I will do that, but what would have caused a perfectly good cylinder to lock when making contact with the switch?
GM Tech (Cam) : I have no idea why. Try it and get back to me. You can reply to this at any time, even after accepting.
Customer : ok, thanks.
GM Tech (Cam) : My pleasure.