Hey guys I’m a new camaro owner, new member, and new to forums. I got a 1995 camaro z28 it had 31k on it but won’t start. The battery was dead when I got it to I put a new one in and the security system instantly started to go off as I was putting it in. Can I just bypass the security system or where should I start looking to find where the issue is. Any help would be appreciated, Thanks in advance.

 

Are you asking about the factory security system (PASS-Key II, or VATS), or does your car have an aftermarket security system installed? When you say "started to go off" do you mean an audible alarm sounded? As I recall, there was no factory installed audible alarm system until the 1996 model year (RPO "UA6").

I'm going to move this to a "tech" forum. Not a lot of technical help available on the "New Member Intro" forum.

 

Yes I’m talking about the VATS, and the siren goes off when the battery is connected.

 

The VATS system does not have an alarm. It consisted of the resistor in the key, the theft deterrent relay that reads the resistor and enables the starter, and a theft deterrent relay that send a fuel enable signal to the PCM.

I looked in the 1995 Owners Manual and the 1995 factory service manual, and didn’t see an alarm system mentioned. The 4th Gen FAQ indicates the content theft alarm was a new feature in 1996. It’s incorporated into the body control module, and up through and including 1995 there was no body control module.

But maybe a 1995 owner can pitch in here with more info.

http://shbox.com/1/pass_key.jpg

 

Fred, you're right the theft protection alarm system was a new option in 1996. The picture below is from a 1996 dealer product guide. To my knowledge, Chevrolet alarm systems have always used the horns and not a siren, so that would be another indication of an aftermarket alarm system and the VATS has never used horns or a siren to alert the owner of a problem.

 

Hey guys so I’ve changed the ignition and bypassed the vats with a resistor the same value as my key and the cars still no starting. Once the battery is connected security light comes on and the turn signals flash, the horn goes off and the cluster lights flashes. When I turn the key the fuel pump kicks on but nothing else happens. I tried to attach a video but can’t figure out how to attach it lol. Any help would be much appreciated, thanks.

 

As Fred tried to say above, the 1995 Camaro had no factory alarm system available. If your car activates an alarm and the horn and light flash, a previous owner must have added an aftermarket system to the car. Without knowing the manufacturer and how that system was wired and operates, I'm not sure how to help. The aftermarket wiring most likely is preventing the starter from energizing, but how that is accomplished is anyone's guess.

I should add, if the fuel pump energizes, the VATS is operating properly and likely not your problem.

 

Depends what he means by “the fuel pump kicks on”.

The fuel pump will always start when the key is turned to “run”, then shut offf after two seconds. Turn the key to “start” and the pump will not restart until the PCM receives the fuel enable system from the theft deterrent module.

If the “SECURITY “ light comes on and stays on, read this (scroll down past the resistance table):

4th Gen LT1 F-Body Tech-PassKey/VATS

 

This was something that was always unclear to me. I knew the pump would normally run until it reached pressure when the ignition was in the run position, but I could never find anything in the manual that specifically described what happened to the fuel enable signal when there were VATS problems. Only that the fuel pump would not run and the starter would not engage. I never really considered if the pump would still in the run position without starting the motor.

 

Pump runs based on a timer in the PCM. It isn't based on pressure. When people encounter slow starts, the problem can be failure to build adequate pressure during the prime. The cure can be cycling the key repeatedly to build pressure and allow the engine to start. In many cases when the fuel enable signal is not received due to failure of the theft deterrent module, the engine may actually start and run for a few seconds, consuming the fuel that has built pressure in the system.

 

I can see the timer symbol for the fuel engage contact on the schematic now that you say that. My next question is what activates this timer. Is it the VATS signal or some other input to the theft deterrent module. If it's the VATS signal, how could the timer start when there is no VATS input. The service manual doesn't explain the internal functions of the theft deterrent module to understand what is controlling each of the two outputs. This what I meant above.

 

Thank for the help guys, I just ordered the bypass module should be in tomorrow. So I should just have to follow the instructions on that link you sent and bypass the tdr?

 

Referencing the 95 diagrams from Shoebox - the PCM receives ignition switched power from fuse #5 in the instrument panel when the key is in “run”, “bulb test”, or “start” positions. Same fuse that supplies 12 volts to the fuel pump relay load side. Would appear (just based on observation) the PCM starts the timer when it sees switched 12 volt power. Turn off the ignition switched power and the timer resets. After it times out, the PCM waits for the 50 Hz fuel enable signal to reactivate the fuel pump. It would seem that once the fuel pump is activated the PCM would have to keep it running even if the 50 Hz signal fails, to prevent the engine from stalling in traffic.

Djackson518:

If you purchased a 50 Hz fuel enable signal bypass module, it MAY solve the problem. But without knowing the details of what modifications were made when someone installed an alarm system, no one can say with certainty that it will fix the problem.

 

I purchased the car from my girlfriends dad who’s the original owner and he says he didn’t put a security system in the car.