Hello... my son and I have been nursing a 93 Formula Firebird back to good health for about a year now, it will be his if/when we ever get it done. Yesterday we were in the home stretch; we replaced the power steering pump, the steering rack and all the tie rods, and bled all the brakes and replaced a rear caliper. We got all this done and test drove it to the gas station, filled it with some premium fuel. Hopped back in it, turned the key to start it and... the dash lit up like everything was working, but no start. After much wiggling of the key cylinder, as well as pounding on the steering column I got it started and drove it back home. I tore the column apart, and I can see the problem is the actual key cylinder, it isn't the ignition switch. FWIW, I guess this is fairly common for these to fail.

I can get a new tumbler with a new coded key from Autozone, they have it in stock for $35. Or I can wait til Tues and order one from a Chevy dealership for probably around $100 (just a guess on the price). My question is... if I get the one from Autozone, will it work? Or does the car's ECU need to be programmed to the new coded key?? If it does, then ordering the one from the dealership would definitely be the better route.

Thanks in advance for any help with this!! Much appreciated!

 

They need to do a resistance check of your current ignition key, and sell you a matching key value with cylinder.

What makes you think the cylinder is bad? Sounds like a classic VATS fault. The 2 small orange(I believe) VATS wires break internally in the column where they make a 90 degree turn by the cylinder. If you are able to hit the column to start the TA, maybe there's an issue with these wires.
At the base of the column, unplug the VATS connector. Check ohms (resistance) on the VATS column side of the wiring connector. Insert the key in the ignition to complete the circuit, and check resistance(ohms) on the column side of the connector you unplugged. Wiggle the VATS wires going up the column to see if you can get an "open" reading.

If the VATS is the root cause, I'd bypass it. Search on here for how tos. If you lived close by, I'd make one for you. Always nice to see a father/son project back on the road.

Kyle

 

Kyle, thanks for the response! I'm in MI, and can't see where you're located (responding from my phone). FWIW, I do have a DVM, and I'll check what you said to.

Here's basically how this played out... a little while ago we were fixing some wiring issues under the hood; the original owner had hot wired the cooling fans to a toggle switch and were rewiring everything back to stock. I went to shut the ignition off and the tumbler froze up in the middle. After much wiggling of the tumbler and beating on the column, it freed up and worked like it should.

The next time it played out was at the gas station; I went to start it and it froze up in the run position, but wouldn't start the car- I couldn't turn it off either, the tumbler was basically stuck in the run position. After another round of wiggling the tumbler and beating on the steering column, it to eventually started, but I did notice the turn signals and power windows weren't working. My initial thought was a bad ignition switch, so I pulled the steering column completely apart (wheel off, clock spring out, turn signal switch out, then I removed the torx bolt that holds the tumbler in), and I tore that all apart so I could see the metal rod going to the ignition switch. I removed the actual ignition switch (electrical part that mounts to the top of the column) and the key tumbler still stuck in the "run" position, I can turn it to the "start" position, but I can't shut the ignition off past the run position... it won't let me.

Based on that^, do you think this sounds like a bad key tumbler, an issue in the steering column itself, or something in the VATS? FWIW, I have the battery unhooked while I'm trying all this. Also, I have mildly familiar with electrical and I can solder. Is making a bypass just a matter of soldering resistors or diodes together after you measure the original key? I searched, but all I found was a company that sells the bypass units for something like $270... and I can fix this for less than that .

Also, if anyone finds this thread and is curious about the Autozone tumblers... I picked one up today and it comes with a blank key that's cut to that tumbler, but the key doesn't have a a chip. Basically the instructions say to take your original key and have a key cutting place replace it with a blank that has the same chip as your original, then have them cut that blank key to the one that came with the new AZ tumbler. Hope that makes sense.

 

Here are some pics... basically it does appear to be a bad wire, but I haven't put a meter on it yet. While I still don't know exactly how these work, it does appear that the tumbler is what isn't allowing this to turn like it should.

Pic of what appears to be a bad wire^

 

One more update... it's definitely the tumbler (the key cylinder) that is bad. With the tumbler out i can wiggle it and get it to turn the way it should, but it is what freezes up. So I'll install that Autozone tumbler... then I'll research how to bypass the VATS... that way I won't need to deal with the problems that seem to eventually come up from that.

 

Honestly, I've never understood why so many F-body owners intentionally bypass a security feature on their cars. If you're going through the trouble to replace the cylinder, why not just spend another $20 or so at the dealer to have them cut you a new key with the proper pellet?

 

A. It's obviously problematic.

B. I can get a new tumbler from Autozone for $35 that comes with a blank key that's cut for the new tumbler, but has no chip. Next I need to deal with figuring out how to get a new key cut to the the tumbler, but one that has the original chip. Or I could pay what I'm guessing will be over $100 for a new tumbler from GM... and I'm not even sure if after I get all that installed that I wouldn't still need to pay them to hook it to their computer and reprogram the car to a new key anyhow.

So I could do all that^, or bypass this BS and never deal with it again. I'm pretty sure at this point thieves have figured out a way to get around the security key anyhow. If I was honestly worried about someone stealing the car, I could come up with a better way than the coded key anyhow.

I'm not just trying to "bypass the security feature" because I can... I'm trying to get the car started the most inexpensive, yet still functional way I can because the POS security key is jeeping ME from driving it (as opposed to a thief).

 

It isn't specifically the VATS that is bad, it's the key cylinder that is bad. I pulled the original cyclinder out, and my volt metwr shows 7.51k ohms with the key in it. Im guessing I could just plug the original tumbler in under the dash and leave the key in it... rather than having a new coded key cut for the new tumbler... couldn't I?

 

With the history you gave, sounds like the cylinder is your issue.
A couple of thoughts-
-If you go ahead and bypass VATS, you can use a blank key with no resistor chip. You would not need a matching resistance key for the car to start
-I agree with you. The VATS will leave you stranded on the side of the road before it stops anyone stealing your car. If you really wanted a security system, install a hidden battery switch or fuel pump switch. Just my 2 cents
- I'm assuming the power windows and turn signal might of not worked if the ignition switch was stuck between the run and start position. There might not of been any contact. My first I thought, the BCM might need resoldered, but something to keep an eye on




Looks like your key resistance is Key #13. You need a resistor to be in-between 7200 to 7820 Ohms. This next pic is the base of the column. The column side (orange) is the female side of this connector. If you find a junk GM car, and remove the seat belt female connector under the driver's seat, it's the same as female VATS plug. Cut off the female pigtail with about 4 inches of wire (under the seat connector). install your 7200-7820 ohm resistors to this pigtail, and now disconnect the VATS at the base of the column, and plug in the bypass female in the the body side male. Bam, you are done. And if you ever want to put things back to original, you haven't cut any wires on the TA.
-Hope that makes since

Kyle

 

It's a wear item, same as anything else. I've had my replacement going strong for years. An AC Delco replacement is $50-70, depending on A4 or M6. Then a little extra for a new key. It takes the same amount of time and work to replace it with a cheap aftermarket.

I understand the frustration, I got stranded a couple times when mine went out. But again, you're defeating a security feature. If that's cool with you, knock yourself out.

 

It's a worthless security feature that at this point hardly works to deter a thief from stealing the car. And it's a problematic security feature, I don't want to send my son off to college in a car that has good odds of leaving him stranded.

But at any rate... the autozone key cylinder is installed, and I left the original cylinder under the dash with the key in it, this works until I get the bypass resistors for it. Ignition rolls like it should and the car runs once again. Thanks Kyle for all the info! Much appreciated!!

 

You are welcome. I found the Part number for that pigtail. It's ridiculous expensive but you have an idea what I'm talking about..
AC delco # PT146
GM # 12085535