C4Finally

It finally happened. Drove my 86 Vert around town last night, made several stops, no problems. Last stop of the night, turn the key and nothing. All dash lights, interior lights, headlights working fine, just no life when turning key. Tried many times and finally called tow truck. About 45 minutes later, just before truck arrives, I try to start the car again and it starts perfectly. Am I experiencing the dreaded VATs issue? How can I keep this from happening if that's what it is? All help and suggestions welcome!

jfb

If you didn't hear the starter solenoid click when you hit crank, then you have a VATS problem. Let me type this one more time! (you can find VATS help by using the search function)
When it won't crank, unplug the clutch safety switch (gear selector sw at the base of the gearshift if auto) and jump the socket. Measure the voltage on the jumper in crank position, there should be 12v on the jumper and the starter should crank. You can verify the starter is ok if no 12v on the jumper by putting 12v on the jumper. If the starter is ok and no 12v, then pull the kick panel above the drivers feet and locate the 2 wires from above the steering column that goes to a 2 pin plug and unplug. Insert your ign key and measure the resistance across the wires, they should measure the same as the pellet in the key. If more than 4% difference, VATS will not allow a crank and won't allow another try for 6 minutes. If more than 4% error, than you have worn contacts in the ign lock that make connection to the pellet and you will need a new ign lock which has new contacts. You can temporarily bypass VATS until the new ign lock is installed by connecting a fixed resistor, a 1/4 watt resistor from Radio Shack will work, across the socket the 2 pin connector plugs into (socket goes to the VATS module). Don't permanently bypass VATS because 99% of thefts are done by bashing the column and jumping the ignition.
If you did hear the starter solenoid clicking but no cranking, you likely have bad contacts in the starter which can be replaced. There are 2 large copper contacts in the starter that the solenoid force together at the end of its stroke that switch the 100+ amps the starter motor requires and these contacts get blackened and pitted with normal use and eventually won't make a low enough resistance connection to run the starter motor. You can keep hitting crank over and over and eventually you clean the junk off the copper contacts to start the engine if the contacts are the problem. Replace the contacts!

C4Finally

Thanks JFB. I appreciate the help...I was getting no solenoid click when trying to crank. It sounds like I have to wait for the problem to arise again before checking the on the jumper, correct?

Can I use the resistor method to rescue myself if I get stranded somewhere?

Thanks!

jfb

Yep, you have to wait, can't fix things that aren't broke. Keep the resistor with you, it'll allow you to drive home!

Loosenut_Beretta

Let me help all of you out, get rid of the VAT's gremlin's forever....

VATS or PASSKey II system modification

If your key's look like this you have VATS
See pic #1 end of post.

Before we begin, here's a question to ponder:

When you insert your ignition key and attempt to start the car, will the car not even attempt to crank over? Does the "Security" light flash during any time you're attempting to start the car?

The simple solution is to first clean off the chip on your key or try another key for the same car. If that also doesn't work, then follow my instructions for a fast, simple, and relatively inexpensive repair.

After performing the following procedure, your vehicle's factory starter interrupter (VATS) will be disabled. A thief will be able to steal your car much easier than if the VATS system were enabled.



Now that being said, I simply found the best way to bypass a malfunctioning "reader" in the ignition lock cylinder. My 92 Buick, was the trial car for this, the wires running from under the dash to the "reader" broke inside the steering column, and I didn't feel like pulling the column apart to fix or replace the lock cylinder. I located the wires in question and created the "resistor pack" to jumper across them.

Just to reiterate: I am not an expert on this system, and know you will say this won't work. It will trust me of the 20 or so I have done they all still work. I can only give 100% confirmation that this trick works on Vat's equipped vehicle's. I have bypassed it on Cadillac's, Camaro's, Riviera's, and Corvette's VATS system.



With that out of the way, here's an explanation of the VATS system:

WHAT IS VATS?

Vats stands for Vehicle Anti Theft System. Lots of people refer to this type of key, as a " computer Chip key". This key or "Chip" has nothing to do with a computer, nor is it a chip. But because of the popularity of calling it a computer chip key, so will we. So that we don’t confuse. The black chip on the blade of the key, is actually a resistor. GM first started using the Vats key in 1986 on the Corvette's, then some of the Cadillacs, ect. GM uses 15 different resistors in their VATS keys. Just by looking at the keys you can’t tell the difference.

How does the VATS System work?

Each VATS key has it’s own unique cuts on the key to operate the lock. but the cuts alone will not allow the car to crank. This is called a mechanical key. Each car has a VATS module (Brain) under the dash that communicates to the starter, fuel pump, and the ignition lock. Each VATS module is randomly given a # (value) from the manufacturer. When the proper mechanical keys, along with the proper VATS chip (resistor value) turns the ignition lock, the VATS module reads the chip on the key . If it is the correct chip, the VATS module will tell the starter and the fuel pump to operate. If the wrong chip is read, the VATS module will tell the starter and the fuel pump to shut down.

How to determine the Value of your key:

By chance you may know what VATS key you now have. Most people do not. There are basically two ways to determine what VATS key you have. Remember, there are 15 differrent possibilities. First, your key can be "read" in a VATS tester. Most locksmiths have these readers, and don’t change anything to tell you. There is another way for you to read the key value yourself. If you have a Volt Meter you can test the OHMS (resistance value) of the chip yourself. Just set your Volt meter to check OHMS, take each lead and place it on each side of the "chip" on your key. A number will appear. Take that number on your volt meter and apply it to the OHMS chart below. Keep in mind that it may not be exact. Just pick the closest value to your reading.

This chart is for any GM product, Buick, Cadillac, Oldsombile, Chevrolet, and Pontiac that has a VATS key (single or double-sided.)

VATS # (K)OHMS (Set your meter to the 20k ohm setting)

1———— 0.402
2———— 0.523
3———— 0.681
4————-0.887
5————-1.130
6————-1.470
7————-1.870
8————-2.370
9————-3.010
10————3.740
11————4.750
12————6.040
13————7.500
14————9.530
15————11.801

Okay, everybody buy their ticket's for this ride?

Tools and supplies needed:

Soldering Iron

Wire Cutters/Strippers/Crimper

Voltmeter/Ohmmeter (DMM)

Approx. 8 inches of 16 ga. wire (speaker wire works great)

"Bullet-Style" solderless connectors

Heat Shrink Tubing

Resistors of varying values (totalling the resistance measured across the key's "pellet") I get asked quite frequently what the wattage of said resistors should be. I've used 1/2 Watt resistors with much success.



Alright, let me begin the madness:

1. Take your DMM, set it to measure Ohms (use the 20k setting.) Measure the resistance across the pellet of the ignition key. Place one probe on the silver part of one side of the pellet, and the other probe on the other side. Write this value down.

2. Purchase a resistor or resistors that add up to the value measured in step 1. Radio Shack is a great place to go for the resistors, heat shrink tubing, and the "bullet-style" solderless connectors.

3. Take the 16 ga. wire and cut into 2 four-inch pieces.

4. Strip off approx 1/16" of insulation off each side of both wire pieces.

5. Put your resistors together in series (or if you're lucky and have a chip that has a resistance that matches a single resistor) and solder one wire to one end of the resistor(s) and the other wire to the other side.

Example: You measure 11.72 on the 20k (k meaning kilo or 1,000) scale. The closest match is 11.801 which is a #15 "chip." Always remember that resistors have a tolerance of 2%, meaning the resistance value of the "pellet" can be either 2% higher or 2% lower than 11.801 k ohms (11.72 falls in tolerance range.) You will want to aim for 11,801 ohms. So when you go to Radio Shack you want to pick up a 10,000 ohm (10k,) a 1,000 ohm (1k,) and an 800 ohm resistors to wire together in series to achieve the 11.801k ohm value.

Here's an example of how you'd connect the above mentioned resistors in "series"

wire------10k ohm------I------1k ohm------I------800 ohm------wire

6. Measure the resistance across the 2 wires now that the resistors are soldered to them. Be absolutely sure the value matches that of the resistor pellet in the ignition key (within 2% up or down.)

7. Cut a length of heat-shrink tubing to cover up the resistors, allowing a small bit to hang over onto each of the 2 wires. Use a lighter or heat gun to shrink the tubing.

8. On one of the wires, crimp on a male bullet connector, and on the other wire crimp on a female bullet connector.

9. Now what you have should look like this:

See pic #2 end of post

Notice in the above "resistor pack" I lucked out and only needed 1 resistor to match the pellet's resistance. You may not be so lucky...

10. Now move to the car. Remove the under-dash kick panel.

11. Look for an orange wire running down the steering column. This wire should have a "rubbery" feel to it, and it is the only orange wire running from the column.

**WARNING** Do not tamper with any of the wires near the column wrapped in yellow harness tape or any yellow wire. These wires are for the airbag. Tampering with any of these wires could result in the airbag discharging.

See pic #3 end of post

12. Cut this wire (there are 2 small wires inside) and strip back the insulation on the wires on the opposite side of the steering column.

13. Install a male bullet connector to one of the 2 wires, and a female on the other.

14. Plug in your "resistor pack" that you made by mating the male and female bullet connectors.

See pic #4 end of post

15. Attempt to start the car. If your problem was with the VATS reader in the ignition lock cylinder, this will start the car.

If this won't start the car, then the problem is in the VATS module. If the VATS module is bad, remove the resistor pack. Strip the insulation off the other side of the main wire cut (running from the column) and place a male connector on one wire and a female on the other. Plug the 2 halves back together to restore the function of the VATS reader.


If VATS is disabled (via your site), then additional keys without the VATS pellet are able to be purchased (and used) at most local hardware stores. The keyblank needed would be an ILCO (or equivalent) B62 blank (this has GM's 'A' keyway, no resistor, and typically was used on Cadillac Allante vehicles). The original key can be cut onto this blank, but the head typically needs to be filed down at the part nearest the ignition lock 2-3 mms. The standard B62 blank will hit the face of the igniton lock, so by shortening the head of the blank, you're in turn lengthening the blank.

You can also trim the key with a dremel tool. Here is a pic showing the new "trimmed" key:

See pic #5 end of post.

You can plainly see where the key is cut by the outline drawn on the paper beneath the lower key.

"AXXESS" brand key, blank #4. The head of the key is longer, and thus can be trimmed to the exact shape of a VATS key:

See pic #5 end of post

I've seen these keys sold at Wal-Mart in the past (not sure if they have them anymore)


Now to conclude the document, I have shown you all a way to completely bypass the VATS module altogether. The VATS module generates a 30/50hz ground pulsed signal to the ECM/PCM to enable the fuel injectors. There is a way to fool the ECM/PCM into seeing that signal. You will need to build your own signal generator with parts from Radio Shack.

If anyone gets stuck or you just want to know how to "wire around" the VAT's like I did in ShamDave's car just, check out the link in my signature.

Picture #1



Picture #2



Picture #3



Picture #4



Picture #5



Picture #6

Loosenut_Beretta

You couldn't have said that to him in a p.m.?

I got lost on this statement.

Wouldnt it be alot easier just to measure it with just the key and a meter?

Ummm no sir, you need a new pellet installed in the key, you dont need a new lock.

You mean ohms?, and just buying one, is not going to do it, because they vary from .4 to almost 12 ohms.

I notice you have been here since '01, and if I offended you by correcting your mistake's, I am sorry. But did you try searching VAT's yourself?, I couldn't find an answer either, that's why I posted a little how to to bypass it.

jfb

I'm not offended and I was the first to offer the procedure to determine what is wrong with VATS. In fact it is the reason why I found the Corvette Forum in the first place.
1. I could have PMed him, but I decided to type my procedure again.
2. If you got lost on jumping the clutch safety sw, then you don't understand how VATS works. Measuring the voltage on the jumper with the ign sw in crank tells you if VATS is working or not.
3. Jumping 12v to the clutch safety switch jumper tells you if the starter is ok. It is important to know if the VATS circuit is working or if the problem is in the starter.
4. My procedure compares the difference between the pellet resistance and the resistance after the contacts in the ign lock. The most common failure is worn contacts in the ign lock that don't make good connection to the pellet. This has happened to me twice in my 87 and was the cause of a no start condition. You do make a good point though and the pellet resistance measurement should be checked against what it is supposed to be.
5. I didn't say you buy only one resistor, and I already said you have to be within 4% of the pellet resistance or VATS will prevent starting. I should really explain that you may have to series/parallel resistors to get within 4%. One poster a while back used a variable resistor set to his keys pellet resistance.

trulytex

I am going to try this Bypass today. I am planning on driving the Vette to Key West this week for New Year's Eve and I don't want to get stranded!

redrose

[QUOTE=Loosenut_Beretta;1571626757] VATS module reads the chip on the key . If it is the correct chip, the VATS module will tell the starter and the fuel pump to operate. If the wrong chip is read, the VATS module will tell the starter and the fuel pump to shut down.

vats does not control the pump, pump will still run for short (abt 2 sec) when the key is cycled on/off with no engine revolve and pump will run when engine is turning ...vats, when pacified, does tell the ecm ok to fire injectors/deliver fuel if dizzy ign module tells ecm that engine is turning.

savy Gm tech told me that 99% of 'vats' failures are actually only the vats circuit starter relay, resistor will NOT help...a 'clip-on' trailer wiring bug at the relay to 'full-time' the starter feed is the 'final answer' to relay failure while retaining vats fuel delivery control if you live in a bad area (check Serv Manual for wire colors at the relay before you jump)

if you only want to do the 'resistor crutch', remember that resistors come within 5% OR 10% of their rated value, last color band of silver indics 10% and last of gold is 5%, rare to find a resistor that is 'right on"...checking a batch of resistors of value nearest your key resistor will often find an exact match... better to build a vats signal simulator for $10 or buy one for $50

trulytex

I still have intermittent VATS problems and have done the following:

Replace the Ignition Switch/Key Switch

Replaced both the the Starter Enable Relay and the Fuel Enable Relay

Grounded out the Starter Enable Relay to the Dash Frame as per the instructions from Gordon Killebrew.


I just made 3 of the VATS bypass wires as per the instructions above and will install it tomorrow (and put a couple in the glovebox). My VATS Code is as 9 which is 3.010. I used a 1.5K Ohm + 1.5K Ohm + 68 Ohm and they tested out to 3.01 and 3.02. They were from Radio Shack and were rated at 5% tolerence.

If this doesn't work, I will have to see about the VATS module next.

Loosenut_Beretta

Let me make it even easier, now this might not be your year diagram, but a pair of wire cutters and two wire pack connectors (two wires get crushed into making one wire) And about six feet of 14 gage wire. make a jumper wire in place of the vats system.

Loosenut_Beretta

A corvette that I totally removed the switch from. I bypassed ithe entire vats system using that^^^ diagram...]





You can bypass your entire vats system, and use a $2.00 dollar key it WILL make it easier to steal! But if you don't tell no-one who's gonna know...

trulytex

Here are a few pics of my install of the Resistor Pack:

Loosenut_Beretta

How did it work out for you?

trulytex

So Far, So Good......

Thanks A Million for all of your Help!

Loosenut_Beretta

good good, I'm so glad to help a gentelman such as yourself.