Pontiacguy18

Hello all,

I've scoured the forums for vats issues and work arounds. Here's some background on my 1991 305 TBI firebird.

Key turns on, starter relay clicks, then nothing. I can jump the starter and turn it. I can manually engage the starter enable relay and the starter will crank with the key. Every now and again it'll start for a second then die.

I tried wiring in the appropriate resistance to bypass the system, measured my contraption with an ohm meter, and plugged it in. I measured it again after plugging it in and it matches my key and my #6 vats range..... Same problem. No crank and no start unless I manually engage the starter enable relay. Sometimes it'll start for a second and then die. Can I rule out VATS? If so..... What the heck do I do next????

I love this car but sometimes..... Sometimes I tell ya.....

Aviator857

Sounds like your vats module is dead. Proper name is passkey module you can find new ones on eBay and other places or you can delete it all together.

I'll post back in a few from computer not my phone with details.

Aviator857

Ok, something a little easier to type on.

First check to make sure the VATS fuse isn't blown... if it is simple fix though it only powers the vats module so if it is blown the question is why...

Here is how you completely delete the VATS.

https://www.hawksmotorsports.com/vat...maro-firebird/ (you can also make your own or src it from others they are a sponsor so linking to them)

This you can wire in, easiest spot is under the passenger dash. There you will find the C207 connector. Look for a blue wire here (I think its blue for all years it is on 89), this is the wire going to the ECU. You have to supply a square sign wave of a certain HZ to the ECU or it will disable your fuel pump. The module I linked to above supplies this signal so all you have to do is give it ground, 12v and connect the signal lead to the blue wire (disconnect the passkey module all together. Then bypass the starter relay in the passenger side kick panel. The car should now run. You may have to kill the power to the passkey module or the security light may stay on. This is completely deleting the passkey module, the resistor trick only works if the module is good and you don't have the right key or an issue with the contacts that read the key.

Alternatively can can get someone to flash you a new ECU rom chip with VATS deleted.

If you decide to replace the passkey module and you go the used route you will want to get one from a seller that can tell you the key resistance. What you will have to do is get a key cut to fit your ignition cylinder with the resistor that matches the passkey module. A new passkey module will burn in the value the first time you use it, after that it can never be changed (well I'm sure you could but you know designed not to be changed)

This will tell you more than you ever wanted to know about VATS https://www.thirdgen.org/forums/elec...pass-vats.html
C207 diagram can be found here for the year car you have http://www.austinthirdgen.org/index.php?pid=19

Pontiacguy18

Thanks aviator! I bought one and will get it wired in next week. I guess I'll wire in a kill switch to the starter enable relay in my bypass to have some security.

I'm at 280k miles on the car and 60k on the rebuilt motor/tranny. I've bypassed my cooling fan due to a bad circuit, tach quit due to a wire short somewhere, and I'm starting to get small rust spots underneath... Body is excellent though. Should I think about retiring this one soon if these problems persist?

Aviator857

Nahh I would buy a wire harness from junkyard. Treat any rust when you see it and keep going. I'm in the south so no rust to really worry about. Grounds are the weak points in the wires on these cars as well as a few distribution blocks. The through firewall connector can also cause alot of shorts. I would go through the wires and fix them right and not continue down the bypass things path.

You can put a kill switch inline with this module, if it isn't powered then the pump and injectors are disabled. 3ed gens are not that likely to get stolen. If in a bad town or leaving it for a while take the coil to distribitor wire with you.

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Pontiacguy18

I like the coil wire idea. Well I got her all wired up and running great. Somehow the 12v switched wire I used cuts out when the brake pedal is depressed but it still works. Thank you for the help, I love this forum!

Aviator857

Good to hear, I would find a better 12v ignition on wire. I also wounder what wire is it that everyone taps into I've seen people say x stops working when I hit my brakes... The 12v line should be cold with key in off, and hot in both run and crank position.

Pontiacguy18

The wire is cold when off and hot in run and crank positions. It is one of the wires to the original passkey box, the ground is through that harness as well. I will try to rewire at a later date..... Eventually considering an ls swap which would require revisions to this fix anyways

Aviator857

That module can work on the LS pcu also but I would just program out vats on a LS swap.