Thread: Pass key III

Hi, Just bought a 99 Grand Prix GTP supercharge and the person that I bought it from had problems getting the key out of the ignition so they had the steering column replaced. So I have a car with a key stamped PKIII on it (this key opens the car doors of the vehicle, not for the old ignition though, as I understand it) and a key that came with the new steering column/ignition. When hooked up battery the horn started blowing, and I unlocked the car doors with old key and that took care of that problem disabling the alarm. But when I try to start the vehicle with the new key it acts like it's turning over but I assume it's not reading the right code or whatever and the theft deterrent module is shutting off the fuel injectors. What do I need to do to get this vehicle running??? Also, I do have a Snap-on MT2500 scanner and have heard that this will detect something?? Haven't had time to check that out yet. Does anyone know if the scanner can override anything to do with this? Any help will be appreciated. Thank you.

Originally Posted by hoffjl00

Hi, Just bought a 99 Grand Prix GTP supercharge and the person that I bought it from had problems getting the key out of the ignition so they had the steering column replaced. So I have a car with a key stamped PKIII on it (this key opens the car doors of the vehicle, not for the old ignition though, as I understand it) and a key that came with the new steering column/ignition. When hooked up battery the horn started blowing, and I unlocked the car doors with old key and that took care of that problem disabling the alarm. But when I try to start the vehicle with the new key it acts like it's turning over but I assume it's not reading the right code or whatever and the theft deterrent module is shutting off the fuel injectors. What do I need to do to get this vehicle running??? Also, I do have a Snap-on MT2500 scanner and have heard that this will detect something?? Haven't had time to check that out yet. Does anyone know if the scanner can override anything to do with this? Any help will be appreciated. Thank you.

I'm not sure why the column was replaced for not being able to get the key out of the ignition. That problem usually lies in either the floor shifter or the ignition cylinder itself.

Your key needs to be programmed to the vehicle. That's easy to do...if you do it in the proper sequence. It generally involves putting the old key in the ignition, turning to run without starting the car, back to off. Insert the new key in the ignition, key to run without starting the car, then off. You should now be able to start the car with the new key.

To the best of my knowledge, a 1999 car should not have a "PK3" key. I'm pretty sure that's for later models like 2004 and up, but I'm not at work to confirm this and that may be the problem. I'll try to remember to check it out when I get to work and confirm this. I'll also check to see if you can reprogram the key yourself or whether you'll need to get the car to the dealership.

Wouldn't the key start the car for a second or two then passlock would kick in and kill the engine in this case? At least thats what my car does every once in awhile. I have a 00 SE with a new PK3 that a dealership made. maybe something else is going on?

According to everything I can see...both the service manual and the parts manual...the 1999 Grand Prix did not have a Passlock system. There was an option for content theft security systems, something I'd expect a GTP came with from the factory.

There are no instructions for programming keys, the OEM key sells for about $9...a Passlock key sells for almost $30, and the ignition lock cylinder case sells for under $100. One with Passlock...the sensor is in the case...usually goes for a minimum of $200.

From the 2000 Grand Prix service manual:

The PASSKey III vehicle theft deterrent system interfaces to a PASSKey III coded key to determine if a valid ignition key is attempting to start the vehicle's engine. If the key identification code is valid, the theft deterrent module sends a fuel enable signal to the Powertrain Control Module (PCM) to allow fuel delivery to the engine. If the key identification code is invalid, the theft deterrent module does not send a fuel enable signal to the PCM. This action causes the PCM to disable fuel delivery to the engine; thus the engine will crank but will not start.
The theft deterrent module can read the identification code inside the PASSKey III coded key in less than 0.25 seconds.
Parasitic CurrentWhile the system is in standby mode, the parasitic current of the theft deterrent module is less than 0.5 amperes.
Normal Vehicle Operation - Start with Valid PASSKey III Coded Key

• With key removed from ignition key cylinder, the system goes in standby mode. The SECURITY indicator stays off.
• When turning the ignition switch to RUN with the proper PASSKey III coded key, the theft deterrent module reads and confirms the identification code in the key.
• The theft deterrent module sends a fuel enable signal to the Powertrain Control Module (PCM). It also turns on the SECURITY indicator for two seconds.

Tamper Mode - Start Attempt with an Invalid PASSKey III Coded Key

• When turning the ignition switch to RUN with a PASSKey III coded key that contains an invalid identification code, the theft deterrent module reads the identification code in the key and determines the code is illegitimate.
• The theft deterrent module does not send a fuel enable signal to the PCM.
• The theft deterrent module sets the tamper flag and runs a 10-minute lockout timer.
• During this period, the theft deterrent module flashes the SECURITY indicator.
• If the ignition key is turned to OFF/LOCK during the 10-minute lockout timer period, the system goes in standby mode. The lockout timer resumes where it left off upon turning the ignition switch back to RUN.
• When the 10-minute lockout timer expires, the system goes in re-learn wait mode. The ignition switch must be cycled from RUN to OFF/LOCK back to RUN to in order to advance to the next mode.
• Upon turning the ignition switch to RUN, the system re-enters tamper mode for a second time and another 10-minute lockout timer is run. When the 10-minute lockout timer expires, the system goes in re-learn wait mode. For a second time, the ignition switch must be cycled from RUN to OFF/LOCK back to RUN to in order to advance to the next mode.
• Upon turning the ignition switch to RUN, the system re-enters tamper mode for a third time and another 10-minute lockout timer is run. When the 10-minute lockout timer expires, the system goes in re-learn wait mode. For a third time, the ignition switch must be cycled from RUN to OFF/LOCK back to RUN to in order to advance to the next mode.
• Upon turning the ignition switch back to RUN, the system erases the previously stored identification codes and learns the new identification code in the PASSKey III coded key. The new identification code then becomes legitimate.
• The theft deterrent module turns on the SECURITY indicator two seconds and sends a fuel enable signal to the PCM to enable fuel delivery to the engine. If the new identification code is from a valet key, the system will not store its value.
• In order to store another identification code from another PASSKey III coded key, remove key from the ignition key cylinder, and within 10 seconds, insert a new key and turn the ignition switch to RUN.

No Coded Key Mode - Start Attempt without using a PASSKey III Coded Key

• When turning the ignition switch to RUN with a key that does not contain a PASSKey III identification code, the theft deterrent module enters the no coded key mode.
• As long as the ignition switch remains in RUN during the no coded key mode, the SECURITY indicator flashes rapidly. Also, the theft deterrent module does not send a fuel enable signal to the PCM.
• The theft deterrent module performs a key code read every 0.25 seconds during this mode. Note that if the system cannot read the identification code from the key, the system will not enter the 10–minute lockout timer. However, if an invalid key identification code is read, the system enters tamper mode.
• To exit this mode, turn the ignition switch back to OFF/LOCK and start again with a different key.

I'd think that "fuel enable" would power the injectors and the fuel pump. In that case, I think the vehicle would crank and not start at all. If it only powers the fuel pump, the engine might start and run until the fuel rail ran out of gas.

Thanks for that info! My car has issues....

Hi all. Well found out that the vehicle was driven in and when the person got the steering column they told the place the year, etc. and they sold them the Passkey 3 steering column. When that was put in by another person, the car never started again. Anyway, got a new steering column (passlock), put it in and still wouldn't start. Then, started going thru the relays under the hood and the ignition one was missing. Put one in and now it starts. Yeah!! Have no idea who did what on that whole problem, but I'm glad they aren't my mechanic.

Thanks for the help. Especially letting me know that passkey 3 wasn't even used til like 2000 on the Grand Prix or I would probably still be trying to figure it out.

Thanks again.