TDM /VATS Bypass

[92 White ssei]

I am trying to locate the tdm/vats module on my 92 Bonneville SSEi
the information i got behind the glove box nothing is there but the air
bag. Please help if you can. thank you.

[sonoma_zr2]

If you are trying to bypass the vats, just locate the orange wire at the steering column. It is actually 2 very small wires inside an orange sheath. You can feel and see the difference from a regular wire. Clip the wire and place your resistor across the 2 wires on the end that goes to the firewall connector, not the end that goes to the steering column. If you need to get to the actual tdm module, you almost have to remove the dash.

[xcbullet]

It was behind the are bag on my 95.

[willwren]

The location of the module is moot. Do what Sonoma posted above.

[sonoma_zr2]

Here is the wire, this location is the C101 connector (at the base of the steering column, near the fuse box). You want to cut and place the resistor across the 2 leads on the connector side.

[willwren]

But the best place to cut is farther up. That connector isn't even visible or accessible on some years. My 93 for instance. Look around the base of the column for that orange sleeve with the two little wires in it, and cut in a convenient spot.

Solder is the best method, and then protect and restrain it well.

[sonoma_zr2]

Yes, I failed to mention this is the wire that goes up to the key cylinder in the column. Find a spot anywhere between.

[sandrock]

Before going through all that trouble...make sure your key pellet is clean and blow out the lock cylinder. Put some alochol or hand sanitizer on the key and run through the cylinder a few times to clean the contacts.

[GXP_vince]

Hey guys! I am here again because I need help.. My 95 takes about 30 mins to start because of this security issue. I did buy http://newrockies.com Bypass but I can not find the TDM connections. I found this post and figured this would be easier to do. I do not know anything about electronics so can some please explain the resistor deal to me and how to perform this fix before I start cutting wires. I would appreciate it..

Side note: SSEi95- google rankings for this site is outstanding.

[GXP_vince]

Couple of questions to add- what size resistor? And am I basically jumping 11 to 12 using the resistor?

[nickdalzell1]

i think you use a multimeter to measure the resistance of your key's pellet. it should give you the ohms and you can find a resistor at your local Radio Shack. mine only had VATS issues in extreme heat/humidity. if it was 100 degrees the car absolutely wouldn't turn over much less start.

Resistors do not have polarity so there is no concern for which wires go where. i think those two in the little orange 'tube' are the ones the resistor goes in between, think of wiring it in like an in-line fuse. just connect the resistor between those two wires in the tube.

[RJolly87]

http://vats.likeabigdog.com/

There is a orange lead that runs above the drivers feet to the steering column, which has 2 wires in it.

[imidazol97]

Couple of questions to add- what size resistor? And am I basically jumping 11 to 12 using the resistor?

You are actually jumping the white wires that go into 12 and 13. But cut the lead as close up to the steering column as you can for the extra length. Extra length makes it easier to work lying on the seat and trying to scrape the very fine white wires to get something to solder to. The fine copper inside the white wires is difficult to bare by peeling the white plastic off and difficult to solder onto.

Search on Yahoo or Bing for VATS resistances to see the values that are the correct numbers. Here's what I found.
http://www.vatskey.com/vats/vatskeylock.htm

There were 15 different resistances used for keys. Measure yours--the guys at Radio Shack probably would measure for you. Get a selection of resistors that total up very close to that total in series. You need to be within 5-10% of that number. Solder them together. Then solder the ends to the two white wires. I suggest putting heatshrink tubing over the outside before you do the final soldering.

Here are 3 youtube videos I looked at when I was having to do my 98 after it burped one day and wouldn't start because of the TDM VATS. The photography is sometimes bad but keep looking and you'll pick up lots of help. I do not recall which is better, so I'm linked all 3.



http://www.youtube.com/watch?v=AKfn7J9CeZM
http://www.youtube.com/watch?v=_oBHpwwc ... re=related
http://www.youtube.com/watch?v=wQPBRD2T85Q

Good luck.

[Bob Dillon]

If you are trying to bypass the vats, just locate the orange wire at the steering column. It is actually 2 very small wires inside an orange sheath. You can feel and see the difference from a regular wire. Clip the wire and place your resistor across the 2 wires on the end that goes to the firewall connector, not the end that goes to the steering column. If you need to get to the actual tdm module, you almost have to remove the dash.

You need the correct resistor, as well. They vary. You have to read the ohms in the chip with a digital multimeter. Once you know which resistor you need, head for Radio Shack and pick up the correct one. They come in a pack of five, I think I paid like $1.25 last time. Toss the spares in your glove compartment-I did have one burn out.

I used the cable from a computer CD rom drive as the resistor holder. Worked perfectly.

[GXP_vince]

Thanks for all the help.. mine comes out to .887 So I soldered a series together to get .888 and it didn't work. But, I had a 1/4w and a 1/2w in series so maybe that could be the issue? It was just flashing Security. One of my buddies who is a electronics guru is putting together a series for me today with 1/2w .887.
This and starter is the only issue I have had with this car. Bought it for $350 at 74k miles and I drive it to work and back every day. Currently 126k. Echo_SSEi would hate me for this considering he showed me the car but wasn't interested at the time.

[nickdalzell1]

do the early VATS systems kill the starter or do they kill fuel + starter both? if it just disables the starter i wouldn't think it'd be too hard to wire in some wires to the solenoid itself and bump it with a push button or find out which part the key hits and just make it work. i know at times my car has the SECURITY light either flash or come on while driving and it never stalls so i would guess it's only taking out the ability to crank the engine, not disabling fuel or ignition like newer models would do.

[RJolly87]

I believe it does both. I have confirmed the starter gets killed first hand.

[nickdalzell1]

then why does it continue to run whenver the light comes on or flashes while driving? for me it seems to only stop the engine from turning over, not keep it from running or starting. in other threads people say their car stalls when it happens while driving. but they all have VATS II or something newer

[RJolly87]

If an issue is recognized when the vehicle is running, it will usually just flash the light.

It's also easy to bypass the ECM side of the fuel pump, I believe you just ground the fuel pump relay, and the fuel pump will run when the ignition is live. The danger however is that it won't shut off if the engine stalls.

Different years did different things, and someone may have fiddled with it before you also.

[nickdalzell1]

my fuel pump only does the 3-second pulse with the ignition on, but engine not started. so i doubt that anyone tampered with it. whenever i get problems with the VATS it never affects driving but only keeps the starter from turning the engine over. if i knew where the wires are or the solenoid was located i'd try my trick and see what happens whenever it goes out the next time (only does it in 100+ degree heat though).

All i know is that on many GM forums, anytime someone sees 'SECURITY' flashing or the symbol with a slash through the key while driving their engine always quits and won't restart. they all have VATS II and above, and i do know that one kills almost everything including starter, ignition and fuel. i am not too versed on the 1992-era or earlier so i am unsure if only the starter dies or all of it as it does in VATS II or above--but since my engine continues to run despite the light (assuming it is already started before the error happens) it would suggest that the early VATS system had no control over the fuel or ignition.