The removal of the ignition switch lock cylinder is the easiest one to start with. With the cover removed, insert the working key, turn to "ON" or "ACC", then insert bend paper clip into the hole on the bottom which should allow the lock to slide out cylinder housing and lock cylinder complete. At this point, just compare shape, length and number of turns like: #1 Lock, #2 ACC, #3 Off, #4 On, #5 Start. If it is the same functions and dimensions then go for it. Door lock requires more parts to remove and working in the dark corners with no place for hands & light at the same time. I made a nine volt wire rig, with resistors to limit current to power 5 while LEDs' on a short length of wire just for this.
If you are looking to install locks that one key works on everything, then you'l have to physically check or ask a locksmith that has that experience.
If service is needed:
The double sided key is supposed to be harder to pick, but don't be fooled. Auto Key lock cylinders are cheap and may have only one row if tumbler pins to move. Many, either single or double sided key, its' has a metal plate on one side and staked in place. The ends will show little dimples on both side of the plate and can be gently loosened and removed with a flay blade screw driver or pick. Just clean it first, wipe off and place over large white towel or paper shop towel to catch all. With one end off, remove the key slowly and you will start with a needle nose pliers to remove each tumble slides with tiny swings under one edge. Place one a sheet of paper. Many have numbers or letters so write it down if found. If your done, assemble with dry graphite only. Dealers and locksmith shops has it, but can be bought online.
These wear more than the cylinder itself where the key pushes them up or down. The GM key cut is using the shoulder to stop and locate the key inside the lock. Imports use the end tip to locate the key. Replacements are at the dealership or locksmith. Each high & low spot on the key, is a location number for punching a new key at the dealer. They don't grind them as for GMT400 go by VIN # on the TECHLine website. The use a punch tool that punches a "V" shape notch into the black. The tumbler slides maybe one half of the number of spots on the key.
Technology passes over trucks compared to cars, so the anti-theft phases it over by just having the correct key cut. You'l need the VIN, title and drivers license to get a key cut. PassLock-1 & 11 are the same with a resistor chip visible in the keys shank. PassLock 1 interrupted cranking for 1 year as PassLock-11 stopped ignition & injectors in 92. GMT400's had nothing. The factory key with nothing stamped on the shank is GMT400 keys. PassLock-111, has a number "3" only on the shank and used the RFID chip inside the plastic key head. PassLock-3+, had the number "3" with a circle over it. This works the same as the RFID chip, but instead of one electronic hand-shank, it has two, by challenging the RFID chip with a new code, then the chip responds in kind.
Push to start:
These use 3 or 4 antennas' located in the dash to establish a constant contact with the RFID chip as long as it is within 1 meter of the "Push" button to start. Once started, the fob can removed from the vehicle with ny problems. People get lazy and leave the fob in the vehicle at home, then get stolen.
Problems with "Push" to start vehicles can malfunction at gas stations in certain conditions. The pump is not "Hard-Wired" to the cashiers pump control panel inside the store, but a "Two-Way-Radio" signal control the pump and this can mess with "Push" to start systems.
The RFID chip is about the size of a grain of rice, invented by a company in Sweden. It came to the U.S. in automobiles with the short lived GM Cadillac Catera from 96-01 and called the "Immobilizer"system.
If you are thinking of aftermarket "Keyless" they have a problem with using a 450hz signal and becomes easy to open with out rolling codes. Thieves now use a hidden antenna scanner to "Capture" the last code sent, by following close by, acting normal. But for certain brands or models, will know the next code used in the "Line-Up" to open and steal a push to start system. So far, not every brand has been hacked.
