Special Information for the VATS bypass
gottabike
10-04-2005, 10:53 PM
For those of you who are having problems where the car wont start due to your VATS system wiring being broken, this is information to make your lives easier. I ran into a problem with getting my key's resistance tested. Radioshack didnt have the answers to my questions, and the dealer wouldnt tell me more than what key out of the series it was. If you are having the same problem i had with the broken wire on the ignition, i recommend to get the key ohms resistance and the wiring job to visit your local alarm shop.
I went to the local alarm shop and he measured my key to the proper resistance of 9,473 ohms close to key 14 on the chart below. He then took a GM resistor used to bypass stock alarms and clamped on clips on the end so its easier to wire in to the line you need. So to save you the trouble of going here and there just visit a local reputable alarm shop they are a big help....
Here are the instructions as well on how to do the bypass. The key chart below is not verified by GM but my #14 key according to the dealer was close to 14 on the chart. I hope this helps out everyone with this problem. The instructions below I accredit to the person listed on the bottom he has been a big help with fixing this problem. Thanks Sid
Instructions:
How to bypass the Buick (GM) “resistor key” security function when it quits working because of a broken wire or worn out key contact:
The symptoms vary, but since this “problem” instructs the security system to cut off the fuel pump and disable the starter, you will find that your car will make no attempt to crank when you turn the ignition switch and if you jump 12 volts directly to the starter, the engine will crank & then cut off.
First you have to measure the resistance of the "wart" on your ignition key with an ohmmeter. You can probably get someone at RadioShack to do it for you. The little metal pieces that stick out to either side are where you measure it. You will need three hands to do this. There are about 15 possible resistances (chart is below). Get reasonably close to the measured resistance with small (1/4 watt or so) resistors from RadioShack. Plus or minus 15% seems to work OK. You could also buy a variable resistor & set it to the correct value.
Resistors vary a bit, so you might want to assemble the resistors and then measure what you've actually got.
This site will calculate combined resistances for you: http://www.1728.com/resistrs.htm. You may need this if the needed value is hard to arrive at with available resistors. I can help if this doesn't make sense to you.
Next you have to find the two little (white on my car) wires under the steering column. These wires are somewhat fragile and much smaller than most of the other wires under there. They run up to the back of the ignition switch. I cut the wires about 8” from where they go into the connector at the base of the steering column (toward the front of the car). The connector may be orange, but this is not always the same on every model car.
Splice the bypass resistors between the stripped ends of the two cut wires going into the connector, not into the ignition switch. I used very small gray wire nuts (they are color coded by size).
Make sure you put the resistance in line with the wires going to the security controller, not back to the ignition switch. It is easy to get mixed up when you are upside down under the dash.
Send me a digital picture of your wires if you have any trouble identifying them.
You may contact me with other questions about this procedure.
This was a good fix for my Buick & several others. It should work for yours.
Please let me know if you are successful with this.
Below is a list of the actual ohm values GM seems to use (it is from another web site, so I cannot verify it).
key number - resistance (ohms)
1 402
2 523
3 681
4 887
5 1130
6 1407
7 1870
8 2370
9 3010
10 3740
11 4750
12 6040
13 7500
14 9530
15 11800
Sidney MacIntyre
Conway, SC
sidcoinc@fastmail.fm
I went to the local alarm shop and he measured my key to the proper resistance of 9,473 ohms close to key 14 on the chart below. He then took a GM resistor used to bypass stock alarms and clamped on clips on the end so its easier to wire in to the line you need. So to save you the trouble of going here and there just visit a local reputable alarm shop they are a big help....
Here are the instructions as well on how to do the bypass. The key chart below is not verified by GM but my #14 key according to the dealer was close to 14 on the chart. I hope this helps out everyone with this problem. The instructions below I accredit to the person listed on the bottom he has been a big help with fixing this problem. Thanks Sid
Instructions:
How to bypass the Buick (GM) “resistor key” security function when it quits working because of a broken wire or worn out key contact:
The symptoms vary, but since this “problem” instructs the security system to cut off the fuel pump and disable the starter, you will find that your car will make no attempt to crank when you turn the ignition switch and if you jump 12 volts directly to the starter, the engine will crank & then cut off.
First you have to measure the resistance of the "wart" on your ignition key with an ohmmeter. You can probably get someone at RadioShack to do it for you. The little metal pieces that stick out to either side are where you measure it. You will need three hands to do this. There are about 15 possible resistances (chart is below). Get reasonably close to the measured resistance with small (1/4 watt or so) resistors from RadioShack. Plus or minus 15% seems to work OK. You could also buy a variable resistor & set it to the correct value.
Resistors vary a bit, so you might want to assemble the resistors and then measure what you've actually got.
This site will calculate combined resistances for you: http://www.1728.com/resistrs.htm. You may need this if the needed value is hard to arrive at with available resistors. I can help if this doesn't make sense to you.
Next you have to find the two little (white on my car) wires under the steering column. These wires are somewhat fragile and much smaller than most of the other wires under there. They run up to the back of the ignition switch. I cut the wires about 8” from where they go into the connector at the base of the steering column (toward the front of the car). The connector may be orange, but this is not always the same on every model car.
Splice the bypass resistors between the stripped ends of the two cut wires going into the connector, not into the ignition switch. I used very small gray wire nuts (they are color coded by size).
Make sure you put the resistance in line with the wires going to the security controller, not back to the ignition switch. It is easy to get mixed up when you are upside down under the dash.
Send me a digital picture of your wires if you have any trouble identifying them.
You may contact me with other questions about this procedure.
This was a good fix for my Buick & several others. It should work for yours.
Please let me know if you are successful with this.
Below is a list of the actual ohm values GM seems to use (it is from another web site, so I cannot verify it).
key number - resistance (ohms)
1 402
2 523
3 681
4 887
5 1130
6 1407
7 1870
8 2370
9 3010
10 3740
11 4750
12 6040
13 7500
14 9530
15 11800
Sidney MacIntyre
Conway, SC
sidcoinc@fastmail.fm
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