Ford Mustang Servicing Guide, Part 2

March 1, 2008
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 lock. (See February 2008 issue of Locksmith Ledger, pages 66-72.) In this article, we address removal and disassembly of the ignition lock, key generation and key programming.

The ignition lock used on the Mustang is made by Strattec (P/N 708556) and is the same ignition found in the Montego, 500, Freestyle and the new Taurus and Taurus X as well as other Ford vehicles.
The lower portion of the steering column shroud is secured to the column with two Torx head screws. After the screws have been removed, the lower portion of the shroud can be unclipped from the upper portion and removed to give access to the ignition lock.

The poke-hole for the active retainer is now easily visible from below the steering column. This lock cannot be removed intact in the locked position, so if you cannot turn the lock, you will have to drill out the lock. (
Once the lock has been turned to the “ON” position, an offset scribe or an ice pick can be used to depress the retainer. With the retainer depressed, the lock will pull easily out of the steering column. It is not necessary to remove the transceiver ring from around the ignition in order to depress the retainer or to remove the lock.

The lock cylinder in Photo 52 is loaded from the rear of the housing and the lock plug must be removed in the same way. The face of the lock shown here can only be removed after the plug has been removed.
The E-Clip on the rear of the lock cylinder can be removed with snap-ring priers. Take note of how the clip is installed, as you will have to replace it in the same way that it came off when you reassemble the lock.
The Strattec 381944 assembly tool is the easiest way to disassemble and reassemble this lock. If you do not have this tool, you will have to cut a mechanical key to the lock, and then cut off the head. When the headless key is inserted and turned, it will allow you to turn the plug and push it out the rear of the housing.

To use the Strattec 381944 tool, you insert the two prongs on the end of the tool into the lock as shown in Photo 55. Once the tool is seated into the lock, it has the effect of shimming the plug so that it will turn. Using a pair of needle-nose pliers, you can turn the plug and pull it out of the housing.

Most of the published information on this vehicle indicates that the ignition lock should contain tumblers 2 – 8. On this vehicle however, the lock contained tumblers 3 – 8 and there was an empty slot where the number one tumbler might have been. This vehicle was fresh from the dealership when I took the photos, so I know that this lock is the way that it was when it left the factory. The moral here is not to assume that any particular lock is set up as some book says it should be, but to always check to make sure.

The black rocker on the front of the plug does double duty as a shutter and as a device to push the lock plug in as the key is inserted. The rocker is held in place with a small plastic clip, one end of which is visible in this photo. Make sure that you grease this part well when you reassemble the lock, so that it will work smoothly.

After that plug has been removed from the housing, the faceplate will fall out of the back of the lock. The tab on the back of the faceplate mates with the slot on the side of the lock plug. Notice also that there are two slots on the rear of the faceplate that link to the groove around the edge of the face-plate. When the faceplate is inserted back into the housing, these slots will have to align with two tabs in the housing.

The two tabs on the front of the lock housing are different sizes to match the slots on the faceplate. This assures that the face-plate can only be installed in the proper position.

After the faceplate has been re-installed into the lock housing, the Strattec 381944 tool is placed over the end of the housing with the prongs facing away from the lock. The tool has a notch to make sure that it will only fit onto the housing in the correct position.

With the tool in place, the lock plug can only be inserted in the correct manner because of a tab on the plug and a matching slot on the tool. Once the plug goes in as far as possible, you will usually have to rotate the faceplate slightly to align the parts so that they seat completely. The lock can be reassembled without the tool, but the tool makes the job much easier.

There are many ways to generate a new key for this vehicle, ranging from obtaining the key code from a key code service to removing and disassembling the locks. The most common method in use when the key code is unavailable is to decode the door lock, deck lock or both and then progression any cuts that are still unknown.

The door and deck locks can be decoded with a variety of methods including impressioning, try-out keys, and specialty decoders. The three most popular decoders are the Determinator, EZ-Readers and Kobra Readers. The EZ-Readers and the Kobra Readers read the individual tumblers to determine the exact depth, while the Determinator uses a system of half-depths and impressioning to decode the locks.

Each system has its own advantages and disadvantages, and I personally use all three. Depending on the amount of wear on the locks, and the physical condition of the lock system, I will use the tool that I think will do the best job on that particular car.

Regardless of which system you use to generate the new key, you will still have to use a diagnostic device in order to program the transponder key into the on-board computer. All Ford, Lincoln, and Mercury passenger vehicles from 1999 and up, with the exception of the Escort, are equipped with a transponder system.

Duplicate keys can be added with on-board programming only if two working keys are available and there are less than eight keys already programmed into the vehicle. In some cases the “Spare Key” function that allows on-board programming for duplicate keys may also have been turned off.

The most common tools used to program Ford vehicles are the NGS tool from Hickok, one of the Advanced Diagnostic tools: T-Code, T-Code Pro, MVP; Strattec Code-Seeker; or one of the Silca tools: the SDD or the TKO.
The NGS tool is designed strictly for Ford vehicles and at one time was the official Ford programming tool used in dealerships. For that reason, the NGS tool is capable of some diagnostic and programming functions that are unavailable with any other locksmith tool. But for simple key programming when the system is working properly, all the above systems work equally well.

Regardless of which machine you choose to use, you will first have to plug in to the OBD port. The OB port on the Mustang is easy to find, near where the driver’s left knee would be. All of the diagnostic devices are powered from the vehicle. They should come on as soon as you plug your cable into the OBD port. If not, check for blown fuses, a low battery or other electronic problems.

If you are using the NGS machine to program your key, the first thing you will have to do is select “Service Bay Functions.” If you are using a different device, you will most likely have to select “Immobilizer.”

After selecting the make and model of the vehicle, you will then have to select the module that contains the programming for the transponder system. In the case of the Mustang, that module is the PCM module.

Once in the PCM module, you will have to enter the “Security Access Delay.” This is a 10-minute delay that is built into the system to prevent theft. Studies have shown that if you can slow down a would-be auto thief for even a few minutes, the number of successful thefts will be greatly reduced.

After the security delay has passed, you can select several different options regardless of the machine you are using. You can erase all of the keys that are currently in memory and replace them. You can add one or more keys to the system without erasing the existing keys – up to a maximum of eight keys. Or you can turn the “Spare Key” option on or off, which will either enable or disable onboard programming for duplicate keys as I mentioned earlier.

The machine will let you know when the programming process is complete, and at that point you can add additional keys by inserting them into the ignition and turning them one after another up to the maximum of eight keys. The system is designed to operate with a minimum of two keys in memory, so if you erase the existing keys, you will have to add at least two keys for the system to work properly. If you leave the programming mode with only one key programmed into the system, you will usually have some type of intermittent problems popping up with the security system.

In addition, on some vehicles there is a setting inside the programming menu for “Unlimited Keys.” If this is selected you can program in an unlimited number of keys. This is usually done for fleet vehicles and will require a NGS machine for the programming.