1997 z28
lost original key. Replaced key
Bypassed vats so the car would start
Car started and ran for 1500 miles no issues

Now every time I turn on the key the security lights and hazards are flashing for several minutes cycli g on and off for the duration that the key is on.
car will start and run but security seems to. E malfunctioning as long as the key is on
Does anyone have advice on how to resolve this ?
having bypassed the vats

 

Does the car have the optional factory alarm? Does it possibly have an aftermarket alarm?

 

It appears to be factory. I located the sensor in the wheel well and unplugged it.
WHen the door is opened the alarm goes off. Ignition off. No sound but the lights flashing and doors will not unlock by switches

 

How can I determine that its factory?
can I reprogram a new key fob having replaced the original key ?

 

Factory alarm will show RPO code “UA6” on the Service Parts Identification label. You would have a blinking red LED on the top of the dash and the shock sensor by the spare.

The key fob is programmed internally to match the keyless entry system in the body control module. It has no way of knowing whether the resistor pellet on the key is the right one, or even there. Bypassing the resistor in the key with a resistor in the wiring (is that what you did?) tells the BCM all it needs to know.

 

I appreciate your help. You have have definitely helped me get this car on the road .
It has a factory ua6 alarm.
I grounded out the wire at the relay below the glovebox to start the car.( Vats bypass).I suppose what's happening is the alarm has been set and I don't know or have a way to disarm it.
When I tried the program function by pulling the radio fuse I had no luck. Probably because the alarm was set. What should I do next?

 

Without taking the time to dig into the factory service manual wiring for 96/97, sounds like all you did is supply the ground to the theft deterrent relay (TDR). That allows the starter to crank the engine. That is only 1/2 of the system.

The starter would crank, but the fuel injectors would not operate until the body control module (BCM) sees the correct resistance from the key. When it sees the correct resistance, it would send a ground to the TDR, and a fuel enable signal to the PCM. Not sure why the engine even started without the resistor.

The BCM includes the PASS-Key II (VATS) system, and the factory alarm system, and controls the parking lights, horn, starter relay ground, and fuel enable system. Sounds like something is messed up if it allows the engine to start without the key resistor, or a resistor wired into the two wires in the steering column for the key cylinder. The BCM is prone to problems with the circuit board connections.

At this point, all I can suggest is downloading the 96 factory service manual (99% identical to 97) and going through the diagnostics for the BCM, security system, and alarm.

https://www.mediafire.com/?40mfgeoe4ctti

 

Thank you for the srv manual. It will be useful. I did replace the key with a key from dealer that was supposed to be the correct resistance key for the car. It did not start so that's when I grounded at the relay. Now it sounds like the key was correct and I did actually have a Vats problem. Grounding allowed for the fuel pump to work. Interesting. I'm going to refer to the manual. Thanks.