Using a small screwdriver, carefully pry the tabs up that hold the transceiver ring onto the lock housing. Be cautious as you do this, especially in very cold weather. The transceiver ring contains an antenna that communicates with the transponder in the key. This antenna is composed of a coil of very fine copper wire and if it becomes damaged, the transponder system will not function, and the car will not start. (Photo 54)
After the tabs have been released, the transceiver ring can be pulled over the front of the lock. Don’t try to remove it completely; just let it hang out of the way as you remove the lock. (Photo 55)
The poke-hole for the active retainer is the very large square opening on the top of the lock housing (Photo 56). You will have to hold the upper portion of the steering column shroud up and out of the way as you insert a tool to remove the lock. Insert the key and rotate it to the position that is marked with a “one” on the face of the lock, and then depress the retainer with a small tool such as a screwdriver or ice pick. The retainer is very easy to hit, even though it is not visible, and the lock will literally jump out of the housing about a quarter of an inch when you push down on the retainer.
At this point, the lock will pull out of the housing easily so you can service it. (Photo 57)
Disassembling the Ignition Lock
The ignition lock, like the door lock, has a couple of odd features. Both the active retainer and the transmission interlock lever must be removed from the housing before the plug can be removed from the lock. In addition, the lock plug comes out of the rear of the housing, so when you assemble it, you will need to have a key with no head so that the plug can be inserted back into the housing. (Photo 58)
The opposite end of the active retainer that holds the lock into the steering column also holds the plug in place inside the lock housing. Removing this retainer is the first step in disassembling the lock. (Photo 59)
The plastic cap that holds the retainer and spring in place snaps onto several tabs on the lock housing (Photo 60). To remove the cap, gently pry the tabs free of the lock, making sure that you do not allow the parts to fly apart.
Remove the retainer, spring, and cap as a single unit and put them all in a safe place. I keep a couple of old-fashioned 35mm film canisters around for holding small parts like these while I’m working on a lock. That way, if I get interrupted, I won’t have to wonder what I did with any parts when I return. (Photo 61)
Next, we need to remove the transmission interlock lever (Photo 62). This lever prevents the key from being turned to the “off” position until the car is in “park.” It is held in place by a metal snap-on cap.
A little careful prying with an offset scribe will release the metal cap. Before you replace this part, you will need to re-bend the tab so that it will once again grip the lock tightly. (Photo 63)
When you lift the cap off, make sure that you do not lose the spring that is below the cap (Photo 64). Put the cap and the spring in a safe place before you remove the lever itself.
With the cap and the spring out of the picture, the interlock lever will lift straight up and out of its slot. (Photo 65) This part needed to be removed because it would catch on the face of the lock plug as it was being removed otherwise.
Photo 66 shows a special assembly / disassembly tool that comes with a replacement lock, but you can easily make one yourself. This is simply a headless key blade that has been cut to a number five depth – the deepest depth in the system – down its entire length. Another option would be to copy the existing key for the lock onto a headless key blade. The purpose of this tool is to make sure that none of the wafers fall out of the lock as we remove the plug from the housing.
Slide the key blade into the plug, and then slide the plug out of the housing. As you remove the plug, watch out for the two inserts that will fall out if you let them. (Photo 67) Also note that there is a hardened steel plate at the front of the plug that will come out along with the plug.
Photo 68 shows the two inserts; the plastic insert operates the key minder switch and the metal one operates the transmission interlock lever. The two parts are different shapes and each will only fit into its own socket in one orientation, so you cannot get them mixed up.
The new Ford Fiesta uses the new high-security side-milled lock system that Ford plans to phase in worldwide. It also has a transponder system that is essentially the same as other Ford products.
Part 1 of our Comprehensive Guide to the Ford Mustang addressed car opening, removing and disassembling the door lock, opening the trunk, removing and disassembling the deck lock and the glove box...