Ok, so i bought this firebird as a project and it is driving me insane. When i bought it the gauge cluster didn’t work. Only the voltage and oil pressure gauges work, everything else was dead. Drove it home and it did great, so i started tearing down the dash to see if i could fix it. Checked all the fuses by the driver door and they were good. Checked all my grounds in the engine bay and under the passenger side dash and they were good also. Checked the plug and the IBCM and it seems to be good. Checked the plugs and the PCM and its good. So at that point I bit the bullet and just bought a new cluster thinking that was the problem. Put the new one in and three lights appeared that hadn’t worked before. ABS INOP, Check gauges, and the seatbelt light. Almost forgot, the radio has always worked, even when i started it for the first time. Also something that was new was the odometer would light up, but it would flash and have the word error written on it. When i would turn on the caution lights the seatbelt light would flash lol. So then i started digging under the dash. I replaced the ignition switch which was a royal pain, and also noticed the VATS system plug was taped up. When i unwrapped it the plug from the steering column was pushed out of the way. The plug from the car had an additional 2 prong plug with two wires tied together. Curiosity killed the cat and i plugged the wire from the steering column into the other plug from the dash. Once i did that the car is dead in the water. It wont do anything, and before it would at least start. I tried replugging the two wire plug back in and it didn’t do anything. I have no idea where to go from here. Any thoughts or tips you guys might have would be greatly appreciated!

 

Sounds like you bought someone else's hack job. Was this a flood car by chance? My guess is someone bypassed the VATS and you must have screwed up however they had it rigged. The only thing I can tell you is that you need to buy a voltmeter and start figuring out where these random wires go. Diagnosing wiring problems over the internet is a fool's errand, unfortunately.

 

Honestly the more i read it sounds like this was a flood car. Of course the guy i bought it from said it had been shed kept and not in the rain. Don’t get me wrong, i got a good deal on it but i had no idea it had issues like this. My question is why wont the same method work for the security system? If they were able to plug up an additional plug why can that work for me? Hopefully i didn’t burn something up when unplugging it up. I bought some resistors and that didn’t seem to work either. Well, maybe i didnt buy the right ones. I used a 10k+- resistor and measured it at 9,980 ohms. A guy i was talking to said my car can tolerate 9,100 - 9,930 and not reject it. I guess me being 0.050 ohms over makes the car not recognize it...

Any other tips and tricks that might make it run, cause thats what im going for at this point....

Thanks for your reply!!

 

I assume you determined the needed resistance value based on the resistors that were in the original VATS bypass. There are 15 different resistance values which were used by GM in VATS. If your car was set to #14 then the person you were talking to was close... the expected value would be 9530 and it will tolerate 9149 through 9931 to match that value, but there's no way to produce that with a 10K ohm resistor. If it was one of the other 14 settings then you're not even close.

Below is a list of the 15 different resistance values and how they can be achieved with common resistors. You will notice that many (most) cannot be matched with a single resistor. The chart lists combinations that will match as closely as possible (the variance is listed with each combination and never exceeds 0.5% which is well within tolerances). Some combinations work in series (connect the resistors in line end-to-end) and others in parallel (connect the ends together so that the resistors are side-by-side). Series connections are noted with + and parallel connections are noted with ||. If you have the original resistors then you should be able to determine which of the 15 values is the correct one. Then you can buy the correct resistors to make up the needed value. The 10K ohm resistor you have is only useful for #9 or #15.

Resistors in VATS seldom burn out (it's a very low current circuit), so I would bet that there's nothing wrong with the resistors from the original bypass - they've probably just gotten disconnected from each other. You could try putting them back together according to the chart and see if you can get it working again. Here's a link to a good resistor color band calculator to assist you with determining the value of each resistor you have (the color codes can be difficult if you're not familiar with them): Resistor Color Code Calculator

 

Alright, sorry for the week long hiatus. Took a trip and had school so its kinda been hectic. I decided to order a vats bypass module with all 15 key possibilities. Ive tried every resistance and couldn’t get the car to do anything. The radio works, nothing on the door locks, and the security light is on in the dash. So, im thinking the next thing would be the BCM? Ive taken it apart and cant find anything wrong with the solder joints or plugs, but i unfortunately think im dealing with a flood car. Maybe it got wet? It still dings when the doors open, and when the key is in the ignition. It also clicks. Like every 15 or so seconds it will click even with the key off.



Another thing, could my PCM be bad? I scanned the car and got 40 PCM codes. Like mass flow sensor, plugs, etc. Didnt think it would be bad as it ran great until the vats issues.... Thanks for the help!

 

If the car was a flood victim then almost any electrical gremlin is possible. Otherwise, it's extremely rare for the BCM to fail just for VATS.(as in... I've never heard of it happening in all the years I've been here). When a BCM becomes faulty, you will have other symptoms such as no retained accessory power, no courtesy lights, no warning chimes, etc.

If you have a ohmmeter or multimeter you should be able to measure the resistance of the resistors in the added jumper you found plugged into the VATS system. All you need to do is duplicate that resistance with new resistors and you should be good to go since it worked before you took it apart.

 

The plug that i pulled did not have any resistors on it. It was taped up, so i checked it to make sure i didn’t miss them and there was nothing there. The two wires on the plug were tied together, so i have no idea how they got the car to run like that....