We finally got the Beast running properly properly period came back from a test drive and shut it off. Now the anti-theft system seems to have kicked in in the damn car won't start. Any ideas on how to completely disable GM Vats system on a 1989 C4? All of the electric door locks Etc have been getting out of the car
A couple of sites have VATS bypass instructions. On my 96 Bonneville I located the wires coming from the lock cylinder (usually one white and one orange) and added resistors in-line that matched the resistance of the pellet in the key. That successfully bypassed the VATS by fooling the computer. You can try this site F-body VATS or call these folks Aftermarket bypass There are places that will remove the VATS prom from the computer for a small fee, More VATS info that way you can use regular key blanks instead of having to try to find a place that can duplicate the resistor value, many of those resistor key blanks are NLA. They also have the bypass kits out on ebay too for a small fee Vats bypass.
Thanks HR. We are trying the resistor Trick Tonight. Hopefully we'll get this Beast running
Well we put in the proper resistor n the key circuit and still no love. Any more suggestions folks?
Do you have power at all, or is the car totally dark? When you try to start the car: 1) does the SECURITY light blink but nothing else happens; 2) do all lights, including the panel lights that turn on when the key is in the run position, go out?; and 3) When you just turn the key to the on position, can you hear the fuel pump prime? Have you had the battery load-tested?
If 1) - VATS is still disabling ignition.
If 2) - dead short in battery, time for a new one. Or, your alternator is tango uniform and you ran on battery power during the test drive. The battery now needs to be charged to crank the car. Confirm by jump-starting the car. Then put the battery on a charger and fix the alternator.
If 3) - good; reach up under the passenger side of the car and smack the starter solenoid with a hammer, then try to start it again.
Check out this website to understand the system better.
The major fault in my 89c4 was a relay behind the center air vent. I was able to clean the relay contacts and get back on the road after being stranded during vacation.
The resistor trick works if you have a wonky key or ignition cylinder.
I socketed and flashed my ECM to not look for the vats, really the best fool proof way to bypass it.
Good luck
Tried all troubleshooting suggestions fixing or eliminating VATS. No joy.
Finally decided to just hot wire starter with a push button start. Jumped solenoid and nothing happend. Went old school and medieval and whack the starter with a hammer. Eureka the damn thing started.
Damn we feel foolish. Thanks for all your help and suggestions. Old starter and are going through and rebuilding to be on the safe side
Glad it worked out. There were other possible solutions, but a wise man told me once to always go simple first and those were the simplest likely solutions for your C4. Resume play!
In reply to conesare2seconds:
Yup.....we over complicated things and spent 4 days chasing a solution for a problem that didn't exist.
Lookout Challengers. We are back in action!!!!!!!
I like the simplicity of a starter button. Keeping with that theme of simplicity, how about a household hammer with a hole drilled through the wooden handle to the act as a pivot point. A string tied to the hammer's head so from the driver's seat you can pull the string and the hammer will whack the starter.
Yeah, sort of a Rube Goldberg solution.
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