Savannah Dan

1991 Firebird, 305, TBI, automatic, daily driver. Drove to my son’s school to pick him up. When we went to leave it would not crank. No history of this problem. Power windows and headlights work fine. Voltmeter reads about 11.5 volts with key in run position. Volts do not drop when key is turned to crank. The only thing that happens when I turn the key to run is the temp gauge maxes out and the indicator light on the upper right, I think, comes on. I’ve seen this type thing with low voltage situations before.

Tried to start in neutral. No help. Ran shifter through its range a few times just in case it’s the switch on the shifter/tranny. That did not work. Downloaded codes while I waited on the wife to come get us. This is what came up: 24 (left over from a bad VSS that I changed already), 32, 44, 53. Looks like I need to look into the EGR system. The 53, system over voltage on fuel injected models, is the stumper.

I’m headed back out to the car now. I am taking my spare set of keys in case the resistor in my key went bad. I’ll try that first. If that does not work, I’ll take a look at the battery terminals. If anyone has any ideas let me know. Thanks.

Trickster

Hello Savannah Dan,
The codes for your car are as follows:

Code 32= Exhaust Gas Recirculation (EGR) Circuit.

Code 44= Oxygen Sensor Circuit (Lean Exhaust Indicated)

Code 53= Vehicle Anti-Theft System (VATS) Circuit.

The temp gauge going up when you turn the key to start is normal.

Trickster

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Savannah Dan

Thanks T, looks like its the battery or the positive terminal. I'll find out sure tomorrow.

Savannah Dan

Well, the battery was about gone, but it wasn't the problem. Time to look at the starter, neutral safety switch, and the VATs.

Trickster

Need any schematics?

Savannah Dan

Looks like its the VATS. No crank and no security light when I turn key on.

Trickster

It sounds like you have a broken wire coming off the ignition lock cylinder in the steering column.

Savannah Dan

I'm going to try to get the car to the house tonight so I can work on it without the 15 minute drive.

DJXero

I had this same problem. In my case, it was the ignition lock cylinder. It had to be completely replaced along with buying brand new keys (since the old ones weren't the same ohms asd the new reader) It got pretty expensive, and it took forever to find. I hope this at least speeds up your diagnostic process.

Trickster

If he has to replace the lock cylinder, he will be able to use the same resistance value in the new keys as what he had in the old key since he is not changing out the VATS control module.

DJXero

oops, I'm sorry. You're right. I forgot that the VATS module was bad on me too. Sorry

Trickster

Now that part of the system is expensive even without the labor. OUCH!!!!!!

DJXero

No kidding

Trickster

That's why I went to a junkyard and got three of them with matching keys & lock cylinders for $20.00 and a couple hours of my time. Fortunately, it was not the middle of summer or winter when I did this.

P.S. They have already been installed in other projects for a nice return on my investment.

John Millican

iTrader: (1)

Just measure the resistance in your key and find a resister of the same value. Now look under the steering column for two TINY wires coning down from the ignition cylinder. They will have a white (color?) plastic connector. Disconnect it and install the resister on the car side wiring. Try to start the car. This will test the lock cylinder to see if it's bad.

Trickster

John,

You can do the same thing by putting the key in the lock cylinder and measuring the resistance through the wires going up the steering column. If the resistace value is different than what you got directly off the key, your problem is in the lock cylinder or its wiring.

mplogic

I'm having this same exact problem in my 92 firebird tbi 305, 5 speed.

Car drove fine friday morning, parked it for an hour or so, wouldn't crank, no security light and getting a code 53.

Spent several hours today checking the fusable links, starter, and clutch switch only to find them all good. I didn't even know my car had a VATS system. Well, I guess time to check that out and the ignition switch next.

Sounds like a common problem, let me know if you make any progress Savannah Dan. Thanks for all the good info guys.

mplogic

Oh and where is the VATS module located? My lame-o Haynes manual doesn't even mention it. Have any diagrams Trickster?

Is there a procedure to reset the security system?

Thanks again

Trickster

The VATS control module is located beneath the defroster ducts on the firewall behind the center console. That unit very seldom goes bad, it is probably a broken wire on the ignition lock cylinder in the steering column. Use a multimeter set to OHM's and measure the resistance value of the pellet in the key. Under the dash, you will see two wires coming from the steering column. They will either be two yellow wires in a black wrap or two white wires in a orange wrap. They will connect to two wires that are black/white & purple/yellow. Disconnect that harness, put the key in the lock cylinder and measure the resistance value through the wires in the steering column. If the value is different from the first reading, your problem is in the lock cylinder. If the value is the same, your problem is elsewhere in the system. I am including a schematic of the VATS system. No, there is no procedure for re-setting it manually, it has it's own built-in re-set timer. And yes, I agree about the Haynes manual as well as the Chilton. That is why I spent the extra money and got the GM service manual for my car. It was well worth the money spent.

Savannah Dan

I still haven't gotten the car to the house yet. I have a bunch of other stuff going on and this is anso my wife's Guard weekend, which leaves me at home trying to keep the four year old from killing me.

I took a ride to the car Friday night just to see if by chance it would crank. I get there and the battery is dead. WTF! Then I realized that the last time I was at the car I turned the dome light on to see what it would do when I put the key to start. Well, my dumb@ss must have left the dome light on!

mplogic

Ok, spent some time under the dash today and spent some more time researching the wiring. The "two white wires in an orange wrap" are labeled with Airbag stickers and everywhere I read it's telling me strictly to NOT probe those wires as it could cause a deployment. I don't think the super low current of a ohm meter would do it, but I don't like tickling airbag wires at all.

Where did you get your info on this? Sounds like something a joker would say to get somone to deploy their airbag... Course I could be looking at the wrong wires all together. In any case, I'd say be extremely careful when messing around with airbag wires, not only could it hurt you, it will also make your car stink and they are expensive as hell to replace (trust me I know).

Well, back to the troubleshooting.

Trickster

Yes, the wires are bundled together on your car with the airbag harness that comes down the steering column also. Look for the two white wires that plug into a connector that has a black/white wire and a purple/yellow wire. These are the two wires for the VATS. The airbag wires should be a solid yellow. The two white wires are wrapped in orange. Here is the only picture I have of it at the moment. This information came out of the GM service manual and I don't think they want a airbag going off in someone's face either.

mplogic

Got it! You are indeed correct Trickster (not that I ever doubted you).

I was able to verify with a wiring diagram that those are not related to the airbad system. Why they label them as such, I have no idea. I rigged up a 5k pot and adjusted it as close as I could to my key's resistor then attached it to the car side of that plug and it fired right up. Also the other side of the plug (white w/ orange wrap) is reading open with and without the key and in all positions.

So the problem is definately in the ignition switch or wiring to it.

Must be a common failure point on these cars.

Trickster

Unfortunately it is, over a period of time the wires will get worn and break either from old age or someone hits it with there foot while applying the brake. Glad you found it and will be able to fix it. If the broken wire (if that's the case) has enough room on it, you might be able to splice it together.

Savannah Dan

I finally got my Firebird back to the house tonight after a $55 ride on a roll-back. Now I can do some proper troubleshooting instead of shotgunning. I'll look at the wiring under the dash when I get a chance.

If I remember right, my airbag wiring is yellow. It doesn't matter though because I always disconnect the battery before messing with a car with an airbag. I can't see risking cr@pping myself when an airbag goes off if I don't have to.

By the way, it's nice driving the Firebird home from work with the tops off, but it sure has been fun driving the Z28 every day again. *** I love that HP and torque. Acceleration rules!!!

Savannah Dan

Had to work a 13 hour day today, but still had to go out to the Firebird to ring out the VATS wires on the coulmn. They read open with the key in. I rounded up some resistors and ended up putting four 1.5k ohms in series to match my key. I back-stabbed the connector with them and it cranked right up. I'll fix the wiring when I go in the column to fix the high beam switch rod. Thanks for the help.