This 1996 Pontiac Grand Prix came in on a hook with a no crank condition. In the automotive world a “no crank condition” is the starter does not work and a “no start condition” is the starter works but the engine will not run but I digress. The first I noticed when I tried to crank the engine was that the security light was flashing and of course the starter did not work.
I checked the key with an ohm meter.
It was good 2.36k ohms resistance. The system allows for a small variation in resistance values.
I located the VATS harness connector at the bottom of the dash.
Tested for a matching key resistance with the key in the ignition. Open circuit. Diagnosis of broken wire at the VATS lock cylinder inside the steering column. Note this vehicle demonstrated an open circuit with the key in the ignition and not even switched on. It may be necessary to fully rotate the ignition key cylinder to the crank position while monitoring resistance in order to find the problem. Many times the wire will not be completely broken and it will only go open when in the crank position.
I installed a bypass unit and cranked the vehicle. I also secured the wiring out of harms way.
Here is a list of factory resistance values for GM vehicles with the VATS system. The VATS system is identified by the ignition key having a resistor chip in the key as illustrated in the first picture. The above key with a resistance value if 2.36 K would match in the chart to a key blank #8. Since the car is a 1996 model it would have a letter code of ZB. This information is useful for buying a replacement key blank and having it cut for a new lock cylinder if you would like to properly repair your vehicle by replacing the faulty lock cylinder with a new part. The new lock cylinders do not come with a key that has a resistor in it. Instead it is a brass blank key with the proper tumbler code cut into it. The correct resistor key blank has to be purchased separately and it will have to have the tumbler code cut into it by a locksmith.
VATS# 93-95 96-00 Resistance
- Disc Disc .402 K Ohms
- CN YT .523 K Ohms
- FW JB .681 K Ohms
- GP EJ .887 K Ohms
- KA UR 1.13 K Ohms
- N5 Q3 1.47 K Ohms
- UN KH 1.87 K Ohms
- XB ZB 2.37 K Ohms
- GA QM 3.01 K Ohms
- NP YJ 3.74 K Ohms
- FY JH 4.75 K Ohms
- C5 ZR 6.04 K Ohms
- XY KM 7.50 K Ohms
- KB ET 9.53 K Ohms
- UW U3 11.8 K Ohms
To the best of my knowledge that is not true. There are later systems that can relearn but not VATS.
I heard u can use any resistor value and switch the car on for 20 minutes the car module will reset and identify the new value.
is this right?
I bought some years ago from an electrical supply company but there are several places on line that sell them now.
what type of resistor did you use and where can i get one for the 95 pontiac grand prix.
Not a dumb question at all. On this particular vehicle there is a two wire connector. the portion coming from the steering column has two very small white wires inside and orange jacket. Each wire is connected to one side of the key resistor with the key in the ignition. So basically you can install it anywhere between the two small white wires. In the last picture in the post you should be able to see the resistor that I make up to simply plug into the harness. the actual resistor is inside the heat shrink tubing.