97Z06

Hello all!

I already took apart the dash to access the ignition. I noticed that someone already did the bypass under the dash board by soldering in the resistor of the same value as the key. One wire was white w/ black stripe and the other wire was dark purple w/ black stripe.
I also want to confirm that there is a coil wire wrapped around the front outside of the ignition with a female 2 pin connector? Is this normal on all c5's or is this a secondary bypass?

My car will not start due to this. I believe someone did the bypass on this car probably 15-20 years ago and the resistors could have failed? I can't get a 2K OHM reading from the resistor. I can only get a 20K OHM reading.

I have provided pictures as I want to make sure these are the correct wires, and not multiple bypasses.

Can anyone verify these are the correct wires for resistors and that they are supposed to read @ 2K OHM?
Also does anyone else have 2 wires wrapped around the front of the ignition cylinder?

Is this normal?

Resistor failed? only reads @ 20K OHM. No reading @ 2K OHM.

Fast one

What does the resistor on the key read?

001pewter

I thought the car would still start just not go over a certain mph before fuel shutoff if the vats had a problem. One of my tabs broke off and I could crank and drive it but it died. I had to cram aluminum foil in there so I could drive it home.

I could be wrong though.

97Z06

I am Vats #1 (392) using this scale from another post:

1 392
2 523
3 681
4 887
5 1130
6 1470
7 1870
8 2370
9 3010
10 3740
11 4750
12 6040
13 7500
14 9530
15 11800

I have have had 3 extra keys made over the years. The original key doesn't read at any OHM, probably due to age. The other keys I have used to work fine. My Security light is on. I have also tested the starter by jumping the purple and red wire above the BCM. Starter turned fine. I am assuming due to the fuel shut off of VATS, the car will never fire up. I have an 6 Speed.

My next step is to order new resistors and duplicate the 392 OHM value and solder it in.

mmartinez

If there is a problem with VATS the car will simply not crank over, many C5 owners believe that there is a fuel shut off as well, this is not true. The fuel shut off occurs if you have low battery voltage causing column lock problems.

Fast one

For now remove the old resistor and replace it with a 10k potentiometer, you should be able to adjust the pot so the car will start unless it's VAT#15. A 10 turn pot or trimmer would work best if you have one.

GCG

Anything could fail, but I'd be very surprised if that resistor just did.

You mentioned you checked it, but you didn't say how much it read.

• What's the value you are reading with your multimeter?
• What are the color bands on the resistor?
• Can you take a close-up picture of the resistor clearly showing its color bands?

Bill Curlee

100% Correct!! That resistor solder job looks pretty suspect. I would start there. Remove it, inspect the resistor used in the circuit. READ the value with an ohm meter. Provide pictures if possible.

YES, that resistor is in the correct position to bypass the Ignition Key Cylinder Key Chip reading sensor. That coil of wire that you see around the ignition switch bezel is the sensor pig tail that would have connected to the connector where the person soldered on the by-pass resistor.

The resistor must match the resistor chip imbedded in the key.

Bill

Bill Curlee

Here is the schematic. See if you see 5 VDC on the circuit.

Bill

97Z06

I wanted to mention the column lock bypass recall WAS done on this car by GM. I realize now that the car has had the resistor on it this whole time, any keys that i have or purchased would have worked regardless of the VATS #. I need to find the actual resistance value of this car. The old key doesn't give a reading. I did take the sleeve off of the resistor. Pictures are posted. It was broken in half, but could have been from me taking the sleeve off? I am going to pull the codes from the car right now and post.

My Security light stays on when I try to crank.
Battery is good as it sits on a trickle charger
Starter is good, as it turned over when jumped purple/red wires.
I wish I had a TECH 2.

97Z06

Below are the current codes I am pulling. I only listed Current. Looks like this is the VATS system.

10 - PCM P0530 H C
10 - PCM P1631 H C

28 - TCS NO CODES

40 - BCM B2723 H C


Thank you all in advanced for the help!

Bill Curlee

From the picture (best that I can see) you have BROWN / BLACK / RED / SILVER resisters. That would be 1000 OHMs @ 10% tolerance each. The two sets that are in parallel equal 500 Ohms So,, If you add them all up, that would be 3000 ohms.

If I got the colors wrong please correct me. They are difficult to read from the picture. According to the C5 resistance chart and the resistance of that UGLY COBBLED together crap, you have a # 9 value VATS system. From the chart- Desired Value 3010, Max Value 2890, Minimum Value 3150 OHMS

You can take your VIN to a dealer and they can tell you what value Key resistor chip you should have from factory.

Man that sure is a hack job!!!!

Here is the resistor value chart for the VATS:

[IMG]https://img.photobucket.com/albums/v...c.jpg[/IMG]




Bill

97Z06

I have attached pictures with a MUCH better camera. I agree, why so many resistors? I am not an electronics expert, but wouldn't it be easier to just use a single resistor that matches the actual VATS value? Why would someone use so many resistors?

GCG

Since the car was fine before this problem, it means that the resistor value they used for the VATS bypass was correct. Why didn't you read it using your multimeter as suggested above?

Even if the "chain" of resistors broke you could set the multimeter to measure resistance, attach alligator clips to the multimeter leads, clip a lead to each end of the "chain" and (keeping your hands on the insulated cover of the alligator clips) touch together the broken point of the "chain" long and steady enough to get a reading. It's fast and not difficult.


What an ugly, sloppy and shitty job they did with those resistors! It would be difficult to make it worse even trying hard!

I asked you to list the color bands because I knew it was going to be almost impossible to recognize the color with certainty from the pictures.

I need you to verify if these are indeed the colors (I'm not going to mention the gold band - that's just the tolerance: 5% in this case):
2 in parallel - brown, black, red (both the same)
1 by itself - brown, black, orange
1 by itself - brown, black, red
2 in parallel - brown, black, red (both the same)

If those are the colors, on top of everything they unnecessarily complicated themselves, and the total resistance should be 12K Ohms to simulate a VAT 15: 11.8K Ohms.

Bill Curlee

The Brown / Black / Orange would make it 10,000 so the total value would be 12,000 The chart value for #15 - Desired Value= 11,800 Min 11,328, Max 12,292
I would go to GM and verify the OEM value.

Bill Curlee

GCG is spot on!

GCG

Bill, I was typing my reply but got interrupted and when I finally finished I saw you had posted something as well.

WHAT AN UGLY JOB!!!! (and unnecessarily complicated)

97Z06

Thanks Bill and GCG for your help and providing me the accurate VATS # of the old resistors. I found a resistor within range provided. Connected it and the car started right up. I do want to thank you guys for all the help! Have a great Memorial Day tomorrow!

GCG

Glad I could be of help!