Thank you for taking the time to read. I got the vehicle the weekend before Christmas. It was a Saturday. Wouldn't turn over Sunday morning. Key in, turn to on and everything comes on like normal, gauges sweep and all lights come one as they should, turn to start all lights go out, can hear the clicking from the theft relay but no crank. Good battery, good anti theft relay, cleaned the battery ground, tried in park and neutral, took to a reputable shop and they found no issues, started for them each time. No codes in the system aside from HVAC codes for the cabin temp sensor which was removed previously and a few for the right side actuator. When it does start, there are no issues, runs great. Today I went to remove the ignition switch and found that it has already been replaced, possibly recently as it looks quite new. I removed the ignition cylinder, cleaned with electrical contact cleaner and WD 40. Used a hair dryer to dry it out. Reinstalled all components and now I have the B2723 C H. This is the first time I've had this code. I cleaned both key resistors with rubbing alcohol and put some on a paper towel and worked it into the lock the best I could, still have the code and security light now stays on when key is in On position. I also got the Service Column Lock on the dash yesterday, never had it before either. Recall for that has been done as my steering wheel does not lock when key is out. The car recently sat for 5 days while I was out of town, started right up when I tried it. Yesterday I used the hair dryer to heat up the cylinder a little as I was thinking that might help the connections inside the switch and cylinder expand so good contact could be made, assuming that when it's colder out overnight in the 30s, that may make starting difficult. I found that as I repeatedly turned the key and moved it around while turning, it caught once real quick but I let go too soon, took several more tries before it started. Aside from replacing the ignition cylinder and key resistor, I'm stumped. Any help is appreciated .

 

Would like to help you figure out what is happening, but I need to know if you are proficient with multimeter?

 

Yes I've used one before

 

You have to verify that the TDR is being energized when you turn the key to the start position of the Ignition switch. The TDR will have four wires, red, violet, yellow, and yellow with a black strip. With the positive meter lead connected to the supply 12v side of a fuse in the fuse box and the negative lead to the yellow black stripped wire with the switch in the run position you should have 12v. The next step is to find a good ground and the other lead connected to the yellow wire you should have 12v with the Ignition switch held in the start position. There is a test you can do that will determine if it's a control problem or a problem with your starter. Take a medium gauge short wire with the ends stripped off and insert in the red and violet wire terminals of the TDR, make absolutely sure the car is in Park or neutral because doing this bypasses those requirements. The car should crank over if there are no problems with the starter, if you leave the key in the run position the car should start.

 

I wasn't able to get out today and check around but I'm hopeful I'll have time to poke around tomorrow. I am fairly confident the relay itself works as I've had it tested and I can hear/feel it click whenever the key is turned. Even with the VATS code it still clicks. I was told by a local shop that the starter looks good and wires are also in good shape. It would start randomly before I tried cleaning the ignition cylinder, got the VATS code after that.

 

I have 12v in On, I do not have 12v in Start. The starter does turn over when bypassing at the relay and it does start but immediately dies.

 

The TDR should only click on when the key is held in the start position. The jumper I talked about will definitely determine if the problem is a control problem or a starter starting to fail or loose corroded cables at the starter solenoid. That jumper will send 12v from the red wire to the violet wire which is the wire that connects to the starter solenoid

 

No click from the relay. It does crank and start when using the jumper but dies after.

 

So most likely the Ignition switch start contacts are not always making up and sending 12v to the Park/Neutral safety switch and then on to the TDR. Brand new Ignition switch contact blocks have been found to be bad out of the box, most are made in China. There is a sticky on this site that shows how to disassemble and clean the contacts, also some forum members have had to bend a tab to correct this issue.

 

The ignition switch that is in the vehicle is not original and looks newer, made in China sticker also. I have an AC Delco on order that should be here Monday. However my concern is that I never had the VATS code prior to spraying electrical contact cleaner and WD 40 into the ignition cylinder.

 

Hopefully the new new switch also has the front part of the switch that contains the contacts that press against the keys resistor pellet. The WD40 may have gotten on those contacts causing the code, if you had a real problem with the VATS the car would not even crank over as the input signal from the key pellet contacts enable the BCM to provide a ground to the TDR.

 

It does not, only the switch. I've already reached out to a dealer regarding an ignition cylinder, new key, and new fob. I'm capable but taking apart the cylinder is beyond me. Besides I'll feel better with new stuff in there.

 

Good deal, just make sure the new key has the same resistance as the old one.

 

Thank you for your help!

 

Your Welcome, always happy to help a fellow corvette owner.

 

Well I got the new ignition cylinder ordered along with two new keys. The tumblers were installed but the new keys wouldn't turn the cylinder. Surprisingly enough, the old key does turn the cylinder. I just installed the new cylinder, hooked it all back up, and it still doesn't crank. Security light does not go out. Still have the same VATS code as before. Ignition switch is new as well. I'm not sure what else to do at this point.

 

You still have to find out what is happening at the TDR, do you have 12v on the yellow wire of the TDR and ground on the yellow black stripped wire. The security light and the VATS code means the BCM is not providing a ground to the TDR. The BCM is not receiving the correct input from the keys resistor pellet, are those two small wires from the Ignition switch contacts plugged into their connector?

 

As far as I can tell I've got everything back together properly. I was able to use a jumper wire to get the engine to turn over previously.

 

Well, I had it plugged in wrong. There is another connector that I assume goes to the missing cabin air temp sensor that looks exactly the same as the VATS connector. I switched them and it started. I feel like a complete idiot. However it starts and runs!

 

Glad to hear you got it resolved, happy vette motoring