One Car - One Key
     By - lawrence.mazza@stratos.net

    I hate having two different keys for my Fiero. There's one for the ignition, and another for the doors and trunk. It seems that all the foreign cars I have owned had one key for all the locks in the car. Only the American cars seem to have this 'feature' and it really annoys me. I have an alarm that locks and unlocks the doors and trunk, so I could stop carrying the second key. But I don't want to rely on that because if the battery dies, I wouldn't be able to get into the car. Since I can't leave 'well enough' alone, I figured there's got to be a way to get all the keys coded alike.

     
    My first idea was to go to the local car parts store and buy a complete set of locks. Well, it turns out that there is no such package. The ignition lock is different from the door locks in that it has different grooves on the side of the key. Several people suggested going to a locksmith, but when I called around, I found out they don't replace lock cylinders. They only change the tumblers, which are the pins that line up in reference to the teeth on the key. If the key goes into all the locks, they can change the pins, otherwise, tough luck. The Figure on the right shows a typical example of GM key coding as taken from the Helms Service Manual.

    Pick a Key
            Well, since the keys have different grooves on the side, neither will go into all the locks. I could see that if I modified one of the keys, I could get it to fit into all the locks. The question is "On which key should I standardize?" If I use the door key, I'd have to take out the ignition lock to get it re-coded and I know that to get to it I'd have to remove the steering wheel. On the other hand, if I decide to use the ignition key, I'd have to remove and re-code both door locks and the trunk lock.

    I decided the effort would be about equal, so I opted for the less costly alternative -- I left the door and trunk locks alone, and concentrated on changing the ignition lock. Upon closer inspection, the only significant difference between the grooves in the two keys is that the ignition key has an extra groove on the right side, so in order to make the door key fit the ignition lock cylinder, I'd have to add this extra groove to a door key. Mind you, this is a 1988 GM automobile with a 'C' ignition blank and a 'D' door blank. Your car may vary, but if you do some investigation, you may be able to do the same with your car.

    To add the extra groove to the door keys I rigged up a small 'milling machine' using a Dremmel with a 1/4" diameter flat milling bit and set the angle to about 45 degrees (Click on the photo at left to see a larger view). I mounted a small screw table to the work bench under the Dremmel to translate the key, then I carefully cut a groove into the door key. Now the key fits into the ignition cylinder as well as the doors and trunk. And since I had three extra door keys, I grooved them as well.

    Groovy
            Then I took the ignition cylinder out, and took it along with a modified door key to the local Pontiac dealer who put in new tumblers for $10. I put the ignition cylinder back in, and now I have all the locks keyed alike.

    -L