Right now it turns (cylinder) to crank and the lights on the panel lights up and you hear the fan etc but engine won't turn over and security light comes on. Before the entire lock wouldn't turn. You turn the key and it wouldn't move. Make any sense? The GM dealership is the one who told me it was measuring closer to a 3 than a 4. I didn't ask any questions. I just know the original measured 4.

 

But the key that read 4 did finally work, just had a problem with sometimes not letting the tumbler turn, right? As I said, the value of the key has nothing to do with letting the key turn, the cut of the key was the problem. You need to go back to the #4 key, as the 3 certainly isn't working out.

 

Why would both crank at one point though? Even my old key cranked the new cylinder twice.

 

The key we have now that is throwing security cranked the car for 2 days with no issues at all. I'm talking about at least 8 or 10 different times as we were making several stops each day. Then it decides at the end of that second day to lock up entirely and the key wouldn't turn at all.

 

That's a good question. But your VATS system was using a 4 before, stands to reason to keep it there. I don't understand why they switched it from a 4 to a 3 though. From what I'm gathering, the #4 key did start the car, but it had fitment problems with the tumbler.

 

I'll just go back and get another key made and we'll have a 4 done again. It will actually be the 5th try but they were so sure this last one was the winner and he told me to throw the others away. I wish we had another GM dealer to try but this one is only 1/2 a mile from me.

 

Whatever they were talking about (3 or 4) wasn't the vats resistor. All of the keys were a 4. Must have been referring to the cut or something on them. Would the powdered graphite mess with the vats system? Can we blow that out or something?

 

Yes it could muck up the reading. Get a spray can of electrical contact cleaner and give it a shot in the slot!

 

Well we got it to turn and it will crank every once in a while. Yet it throws security 95% of time trying to crank. It will sound like battery is dead when it does this but it measures fine with tester. For kicks my husband tries jumping it with another car while ago while it's throwing one of its fits and it cranks right up. I'm assuming if there's a problem with the starter it wouldn't let you jump it off with another car, right? If it's the VATS would it let you crank this way?

Most of the time here at home it will work fine but 100% of the time that I drive it to work, it will NOT crank when I get off which is after 10 pm. I normally only work 5 hours at a time too so it's not like it's there long enough to kill battery. I even take my voltage tester everywhere with me.