QuestionQUESTION: Hello there, The car I am discussing is a Pontiac Trans AM 89' model with a small block chev. The key with the chip in the head has been lost. Pontiworld (In Australia) have sent a new ignition with a steel key as they have had a computer problem and don't have the information on the resistance value for the key needed. I have replaced the ignition ran the cable down the column and am now having problems getting in the car started. I am aware there are 15 different resistance key chips available. I have used multimetres to take a reading of the plug the ignition connects to (6.45 Ohms) and i was lead to believe it was a number 12 chip (rated at 6.040 Ohms, but i don't know whether that is how you determine the chip value. I have put both those resistances across the ignition wires and haven't had any luck. The paper work received tells you how to put resistors (the same value as the key across the two wires to bypass this system, but I am looking to find out how I get this resistor value to get this car going.
Look forward to hearing from you,
Thanks, Wade.
ANSWER: Hi Wade you correct as to how to bypass the system. but your going about it the wrong way. You need to know what chip the car was shipped with from the factory. The RPO tag in the car's glove box or in the spare tire jack cover has the tag. One of the codes on that tag will determine the correct chip # the car is set up with. once you find that out then you can do a google search for chip # vs reistance chart and there are a lot of them on the net. Then you cross the wires in the steering column with the same value as the chip was in the original key. It sounds to me like you were measuring the wires in the car??? If you have no one at a daler that can help you out then This is the only other option you have is to get a new pass key module. and the module learns the key reistance on the first crank of the car. so whan ever reistance you have installed to bypass the lock cylinder will learn to the new module and you should be able to get the car back on the road.
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QUESTION: Thank you very much for your reply. I will check for RPO tag in the places you mentioned. Yes, I was measuring the plug on the car, but the paperwork was saying to measure the key (A wiring diagram I saw also said the resistance at the plug was a fixed value - and not to measure it) but I was only going off what I was told. I can also pay for the 15 different resistance value keys then I was just going to cut the wire from the old ignition (which is damaged) plug it into the car and touch each wire on each chipped key and try to start the car with the new ignition in the column (So I dont have to cut every key to try it)
Do you think this will also work?
ANSWER: That will not work. the reason being is the system has a shot and long tamper mode. You get like 2 tries starting it with a wrong key and the car goes into a long tamper mode and you have to wait 30 minutes before it will allow the next key try. You'll be there all day long. The method will work but the time is the issue also trying to get a good contact between the pellet and wires will be an issue with out adding the resiatnce of you fingers into the mix. I would Just try the RPO code thing first. Any GOOD dealer ther should be able to help you out. If the RPO tag is missing off the car your gonna be in trouble..
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QUESTION: Thats no good to hear, Cause I came across a page on the net that was also saying to plug in another ignition and test the keys the same way I mentioned. I got all the information off the sticker in the glove box, just not sure which numbers to start with and I wasnt able to locate a web site that would do the resistance vs chip# chart. Do you know a page I can visit? Will it be the big number at the top? or in the sequence of 3 digits in the 6 rows by the 13 columns? I have 15 keys on there way now, so that will help if I can convert the code from the car. Thanks again.
AnswerI'm not sure which one of those codes is the correct one for the key pellet code. I'm not a prts guy I just Fix'em . When you find out which code is the correct one and which key # you need I'll dig throgh some old service manulas and see If I can fid what the resiatnce value is for the key # you need let me know.
