IstV8n

Hello guys. I have a problem with the vats. The symptons are:

No security light on, it wont crank at all. I have got spark fuel pressure fine neutral safety switch is fine starter relay is fine so it looks like everything is fine. Any idea guys?

TPeye

When you say the starter relay is fine, do you hear it clicking when you try to start the car?

Schrade

VATS problem can be lots of stuff, including lint, pocket jam, greasy finger jam, even fried chicken grub jam on the chip in the key.

And all that jam can get in the key slot too, like bad lovin' with a street-corner garden tool (a 'ho').

Tuned Performance

iTrader: (92)

https://www.thirdgen.org/forums/tech...-i-bypass.html
IF you would like the vats bypassed for good send me a pm. If you state what year and induction type you are running I will let you know what wire the ecm is receiving the hz signal. If you are going to repair the vats start with measuring the resistance of the key pellet. Then insert the key into your lock cylinder and disconnect the two white wires at the column and measure the resistance . Going much further even getting to the passkey module is a real pain.

Tuned Performance

iTrader: (92)

If its like your profile B6 of the 165 ecm receives 30hz signal at 50-60% from the passkey module to enable the injector pulse and ground the starter enable relay. not all memcals have the diagnostic code 46 enabled.

vetteoz

iTrader: (13)

Got a spare key to try?
As noted above if the key is worn / dirty or the contacts in the Ign barrel are the same then the VATS module won't be able to read the key correct.
No key read , no fuel or starter

Read
https://www.thirdgen.org/vats_passkey_system

IstV8n

I will let you know on monday because the car is 1200 miles away from me unfortunately and i cant remember if its clicking or not! The guy grounded one of the relays or switches and it did crank but still didnt start. Got spare key i will send that to the guy. He measured the resistance of the key and that is the same than the spare keys.

vetteoz

iTrader: (13)

Starter enable relay ; part of VATS.
Unfortunately VATS also takes out the fuel supply (via the injectors ) which is the reason you still had no start with the relay bypassed

All very well but as I noted , if the contacts that read the key are not doing their job , then a different key may not help.
Check/ clean the contacts 1st

IstV8n

Does the pass key module sends a signal to the ECM if the pass key module receives the wrong signal?

Tuned Performance

iTrader: (92)

If the passkey module does not have the correct resistance from the key pellet it will not send a signal to the ecm or ground the enable relay. his still doesnt mean the relay can't be faulty allowing you to crank the engine but still not have a signal sent to the ecm allowing the injectors to pulse.

IstV8n

Thank you! That's happening at the moment so the fault is somewhere before the pass key module! I let the guy know tomorrow about this and will see! Thanks again for your help again and I will let you know what was the problem! This vats is annoying a bit but I think we just need to understand properly! Also I would like to keep this car original so I will never give up!

vetteoz

iTrader: (13)

Read

https://www.thirdgen.org/vats_passkey_system

IstV8n

Thanks for the link. I do understand how does it works I dont understand how to do the diagnostic so the link was useful. The guy had no time at all so no changes. Maybe he will be able to start on friday. I'll keep you updated later.

IstV8n

I sent an other passkey module which is used and came off from an other harness. The guy plugged it in and now the security light comes on but off course the car doesnt start. I think the pass key module cant relearn. Am i right? And also is there a way how to find out what resistance needed?

IstV8n

It doesnt click at all. sorry for the late answer

stealtht/a

iTrader: (1)

The module can't relearn, it is matched to the key. You need a module with the same number as the original.

IstV8n

Somehow i managed to send the same module. The only difference it makes that the security light comes on but still no crank no start. Any Idea guys?

IstV8n

I've got the full service manual now so hopefully it will help. I will let you know guys whats happening.