1999 Buick Lasabre no start, no crank and no blinking security light.
You've probably fixed it by this time, but I'll offer this: There's a microswitch in the ignition lock cylinder. When you insert the key, turn it & go past the run, to start position, the PassKey module wants to see the correct resistance from the pellet in your key. If it matches the pre-programmed value, it will complete the circuit of what is known as a "Wheatstone Bridge " in the module, and allow ignition, cranking & fuel systems to operate. If it doesn't see the correct value, it will shut down for like 5 minutes or something, then reset for the next try. The problem is, that after innumerable cyclings of the key, one of the the two wires will separate internally, disabling the system totally. The two wires exit the lower end of the steering column, & are a very shiny white, and orange in color. They terminate in a connector that can be disconnected. Do that. Then take a measurement between the two exposed wires in that little black pellet on your key, with an ohmmeter & obtain a resistor of the same value. Don't worry about the wattage value of the resistor....a 1/8 watt resistor will work just fine, as there is minimal current in the circuit. Insert the resistor into the two wires that go into the wiring harness (Not the two going up into the steering column). If the microswitch was at fault, your problem is now cured, although your PassKey system is now disabled. The upside is that you can now have spare keys made from the cheap blanks without the resistor in them. Good luck.
on Sep 30, 2019