vats bypass

I have found the vats wires in my 1997 grand am. yellow,black and yellow/white.I cut the yellow with the car running and the security/theft light came on.Turn off the car and start with the remote start everything works normally with the theft light on.took the resistor reading came up with 1554ohms.Put 1554 ohm resistor to the bcm side of yellow wire and attach the other side of resistor to the black wire.theft light still on.Turn off car and start with key.the theft light goes away.use remote start and car cranks but wont start.Do I cut the black wire and put resistor between yellow and black on bcm side the black wire is still joined and uncut.

Any info would be appreciated.

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Manny

Here is the complete Audiovox Passlock 1 method of bypassing the immobilizer system during remote start using relays :

https://documents.audiovox.com/700056.pdf

Any possibility that the remote start wiring is wrong?

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Soldering is fun!

I followed the wiring  schematic I found on the 12volt board.I even used the third ignition wire  that has to be used for remote start.I am assuming that the ignition wires are all positive . With the vats switched off and the theft light on the remote start works everytime.

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Manny

By "vats switched off" do you mean the Yellow Passlock1 wire cut and no resistor / relay connected?

Were you having intermittent start-up problems with the key before the upgrade? 

Sounds like you might have the wrong resistor value.  Try the measuring procedure again.  I usually try to get within +-2%.

     

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Soldering is fun!

I cut the yellow vats wire and installed a switch.There were no problems with the vats system I just want to put a remote start in the car.I have used DEI bypass modules before but I find that they are not that reliable. When I first turn on the ignition and test resistance I get 1647 ohms. If I keave the ignition on for a while it drops to 1544 +/-. 

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Manny

You could use a 0 - 15K ohm multi-turn potentiometer and set the desired value with a DMM.  Connect it to the Passlock1 wires and try a remote start.  Keep adjusting the pot until you get consistent starts, then obtain a resistor in that value to install permanently.

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Soldering is fun!

I was looking at the schematic and I have already added a relay for the third ignition.I see the bulb wire relay.Should i tie into the start wire and have it power the relay for the bulb wire as the picture describes ? The resistor relay is pretty self explanatory. Does the bulb wire have to be tied in for the remote start to work with the vats system?The only thing I have done differently is I used  one of the ignition outputs to trigger the relay for the third ignition.I dont think that matters but I could be wrong.

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Manny

My information indicates that your 1997 Grand Am has the Passlock1 system.  The VATS system
differs in that the resistor is in the key, there are only 16 different resistor values, and
there are only two, light colored ( white, white or white, violet ), thin wires in a Black or
Orange tube coming from the ignition switch.

Here is the Passlock1 bypass write-up and diagram from Omega :

https://www.wiringinstructions.com/v2/diagrams200/233%20-%20General%20Motors%20Passlock%201%20System%20Interface.pdf

The Bulb Test circuit is important and necessary.  On Passlock1 vehicles I usually use
the iDatalink ADS TBSL PL bypass module with excellent results.

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Soldering is fun!

I think the reason the car didnt strart by remote was because I didnt have the bulb test wire hooked up to the system.I will hook it up and try again.Thank you for all your help.

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Manny

passkey resistance 1546 ohms.My resistor 1568 ohms still well within the 5% required remote start wont start car.Used audiovox schematic in previous poststill nothing. Does the bulb test wire show ground at rest. 12volts ignition on and ground again in crank?Im getting a little frustrated with this install!

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Manny

Sorry, Manny, never tested the Bulb Test wire.  According to the Omega write-up at bullet point #6,  the Black wire rests at ground
when the ignition switch is off.   Perhaps another forum member has some insights on bypassing the Passlock1 without a module.

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Soldering is fun!

the bulb test wire goes to ground while cranking, it is a black wire in the harness with the 2 constant red wires, if your using an audiovox unit use the BLACK / YELLOW wire tied directly to the bulbtest wire, your car has passlock1 not vats and passlock 1 is proper resistance and ground during crank on bulb test( kind of a second start wire only negative)

unit I have is an Ungo.It has the negative output for second start,ignition,accessory.Can I use the second start - direct or do I have to use a relay  on the black bulbtest wire.

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Manny

I'm not familiar with ungo but if you program that wire as a second start it should be fine

I have the proper 1546ohm reistane with my resistors but when I tie into the black passkey wire the resistannce drops to 1044ohms.

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Manny

if you use kregs link to the passlock pdf you should be fine,or if your not comfortable with relays i would recommend a bypass module specific for passlock 1, but you will still need to fire up bulb test as thats not done thru data