VATS Bypass

[nascar24jd]

Hi everyone. 1993 Firebird, 3.4L. I did my research on here already but I have a question. My Security light keeps coming on while driving the car. The car always starts fine, the light just continues to turn on while driving. I have cleaned both keys but I am still having the problem. I am thinking to bypass the VATS system. Here is my issue. The ohms reading that I am getting on a 20k scale is 7.46. I believe that would equal 7460 ohms. I though that these systems were usually set at whole numbers, such as 7500 ohms. Do you think the proper number is 7500?

In addition, what do I need to buy from Radio Shack? I found a 5 pack of 1.5K 1/2W resistors. That would equal 7500 ohms. Can I just twist them together, solder, and connect the assembly between the two wires?

Are 1/2 watt resistors ok for this application? I saw 1/8w, 1/4w, 1/2w, and 1w.

Thanks for your help...

[cantrip]

Re: VATS Bypass

Why bypass it if it starts fine? I would learn about it but I wouldn't do it until the car actually doesn't start.




http://shbox.com/1/how_tos.html

Go down to 23,24, and 25 for info.

I did it a while ago, wasn't too hard.

(sorry for not answering, I'm too tired, lol)

[nascar24jd]

Re: VATS Bypass

Update...

It began to not start intermittently. Wait 3 minutes, then it would start fine. In addition, while driving the security light kept coming on. I traced it to bad contacts in the ignition lock cylinder. If I wiggled the key while driving the Security light would illuminate.

So, this morning I completed the VATS Bypass. I used a Radio Shack potentiometer and it could not have been easier.

10 minutes to prep the potentiometer and 10 minutes to install it into the car.

No more Security light issues ever again. :cool:

[nascar24jd]

Re: VATS Bypass

Well, it has now been 2 days and I have not had any issue with the Security light. Looks like the problem is gone for good.

For anyone having any VATS issues, this is the easiest and cheapest fix ever. I highly recommend using the potentiometer rather then a bunch of resistors. The total repair cost was under $5.

[Mogobs30th]

Re: VATS Bypass

I used resistors, cost me about a $1.20. I used resistors because cars vibrate, which could mess with the potentiometer down the road. But it still works nonetheless.

[nascar24jd]

Re: VATS Bypass

I thought about that, so after I dialed it in I put a drop of 5 minute epoxy on it to lock the shaft. It ended up locked at 7510 Ohms, close enough for me. Then I wrapped the entire piece in electrical tape and zip tied it to the wiring harness under the steering column. I am just happy to have it fixed.

[nascar24jd]

Re: VATS Bypass

The saga continues...

Security light came on yesterday and car would not start. Using my volt meter I have determined that the VATS Decoder Module (1993) is no good. This module was later the Theft Deterrent Module (1994+). The Ohm reading is perfect at the Decoder Module so I know it is not a wiring issue.

I can get the car to start after the 3 minute timer expires, but for trouble shooting purposes I disconnected my potentiometer so that I could get the Security fault to appear.

I bypassed the Starter Relay (Theft Deterrent Relay) so the car will crank even with the Security light on (Ref: Shbox.com). However, it will not start because the ECM is missing the fuel signal. I found a Bypass Module on Ebay and bought it tonight. Shbox.com explains what it is. Basically it will send the fuel enable signal to the PCM and the entire VATS system will them be eliminated. No more key bypass needed, nothing needed.

I have gone this route to eliminate the entire system. I searched all over and cannot find the original module for sale anywhere. The following is clipped from the Shbox website:

So, you just want to get rid of the whole mess?
You must do these things if you don't intend to have any of the components operational:
Bypass the TDR (to allow starter operation)
Purchase a bypass module or have the computer reprogrammed to ignore the need of the signal from the TDM [BCM] (to allow fuel to the injectors)
You won't have to worry about bypassing the key lock cylinder if you intend to no longer use the TDM[BCM] at all for PASS-Key functions.

This has been an interesting experience. I am posting all of this on here so that if somebody searches for the same problem in the future they will find the solution.

After the module arrives and I install it I will post the results.

[ssms5411]

Re: VATS Bypass

If it is the connections inside the lock cyln. then I would just get a new column and bcm like I did for $85 shipped. I got on ebay from Clevland auto parts was a 01' SS A4 , the M5 columns are different depending on year so your need to check if you have a manual , but A4 are all the same ,including BCMS.

[nascar24jd]

Re: VATS Bypass

The column wires are already bypassed. Also, the '93 did not have a BCM, it has a Passkey II Decoder Module. Very hard to find the right one. Thats why I bypassed the TDR and ordered the bypass module to simulate the necessary fuel signal. Hopefully it all works out in the end. The car still starts and drives fine, but every few times it will have the Security issue and I need to wait the 3 minutes and try it again. That is not good...

[3.4orNothing]

Re: VATS Bypass

tune it out

[nascar24jd]

Re: VATS Bypass

tune it out

How? 1993 3.4L A4

Do I send it somewhere?

[3.4orNothing]

Re: VATS Bypass

How? 1993 3.4L A4

Do I send it somewhere?

www.pcmforless.com www.madtuner.com

[nascar24jd]

Re: VATS Bypass

Thanks for the info. I am going to try the Bypass Module for now. Tuning it out would be a better permanent fix, but it is more expensive and the car will be down while the PCM is away. This is my DD so that really won't work for me.

[nascar24jd]

Re: VATS Bypass

For anybody that ever needs to know, the VATS Decoder Module or Theft Deterrent Module on a 1993 Firebird can only be accessed by removing the radio.

Contrary to the info found on the web, this is the only way to access it. You might be able to access it by removing the top of the dash, but I am not sure. While searching on the web I found people saying it is mounted to the firewall, under the glovebox, attached to the SRS Module, etc....

This morning I unwrapped the harness and seperated the three wires I need to tap into when the bypass module arrives in the mail. I only need to tap into Keyed 12v, Ground, and Fuel Enable. I can do all the wiring through the radio access hole and it will come out nice and neat.

[3.4orNothing]

Re: VATS Bypass

Thanks for the info. I am going to try the Bypass Module for now. Tuning it out would be a better permanent fix, but it is more expensive and the car will be down while the PCM is away. This is my DD so that really won't work for me.

it is more expensive but adds you some hp down the road too..