Backyardcarguy

Wondering if you can have partial VATS problems??
As I understand or start to understand the VATS system you have the no crank function and also no injection function.

I have or had a Code 46 appear however the engine cranks but will not fire. From my reading of the system the key resistor controls the crank/no crank portion of the system, what then controls the fuel injection system?? And how can I test this portion of the system??

Thanks

hcbph

I believe the results of a Vats engagement is as you described. I have not tried this, but I've read that if you jumper the starter (a start button) that if the vats system is the cause the car will still start this way.

Sorry, that's all I've read about. Good luck

Paul

markKlein

I'm pretty sure it is not VATS. I believe everything is controlled by the key resistor.

89onlyZ51

You are correct in that the VATS affects both fuel and cranking. Basically, there's a VATS module that reads the resistance of the key pellet, and the VATS module then does two things: 1) sends a signal to the ECM that it's OK to enable the fuel injectors to fire and 2) provides a ground to the starter enable relay to allow cranking.

The two failure modes of the system I've seen/experienced are: 1) the wires in the ignition switch that are supposed to contact the key pellet don't and 2) the starter enable relay goes bad.

Assuming no one has monkeyed with the system, in the case of failure mode #1, you get no fuel or cranking. For #2, you get no cranking, but if you jumped the starter motor, you would get fuel and the engine would run.

See http://www.joestradingpost.com/vats/ for a lot of good information on how the system works and how to diagnose/bypass.

antfarmer2

I would shoot some fluid in it and see if she fires if it does look at fuel system if not spark

Vic'89

Put a noid light on the Injectors and see if they are pulsing when you crank it.

Vic

Backyardcarguy

Thanks Paul
Much appreciated!!
The car does crank with the key switch, but it will not fire and I had a code 46 appear when I checked as the check engine light was on.
I will have to look a little bit deeper.

Regards

Backyardcarguy

Thanks Vic

I will have to get a noid light and see what is happening.

At first it the engine would crank and fire but not run, which I then thought the engine was just firing on the cold start injector?. But then I had the check engine light come on and give me a code 46, thus I assumed it might just be 1/2 of the VATS system causing the problem.
Looks like I will have to gig a little deeper>

Regards

hcbph

If it cranks, it's not the VATS from everything I've read and know.

Cliff Harris

Sometimes people bypass the starter enable relay. If that is done the engine will crank even if it has a VATS problem. The ECM error code 46 tells you that the ECM is not getting the correct signal from the VATS module.