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Old Mar 13, 2021 | 12:47 AM
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Default Vats

Looking for someone to remove vats from my computer in the Houston TX area. Car is a 1994 Corvette with a obdll connector and obdl system.
Car doesn't start at times. Usually will restart in 20 min. Help me out.
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Old Mar 13, 2021 | 07:05 AM
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Originally Posted by dc6902
Looking for someone to remove vats from my computer in the Houston TX area. Car is a 1994 Corvette with a obdll connector and obdl system.
Car doesn't start at times. Usually will restart in 20 min. Help me out.
It might not be VATS system, if it's start after 20 minutes my C4 had that problem and drove me crazy.

If your problem is like mind, which others will tell you they experience the same problem is your STARTER is seize up, and when cools down, starts like nothing is ever wrong.

I would check and if it's your problem replace your starter and install a heat shield to prevent it to happen.

Good luck.
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Old Mar 13, 2021 | 08:19 AM
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My thoughts also. I don’t think it is a VATS issue
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Old Mar 13, 2021 | 04:24 PM
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I thought it was too. Replace starter and a relay also. Ignition bypass too.
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Old Mar 13, 2021 | 11:09 PM
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Key resistance has been bypassed. I forget word for it.
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Old Mar 14, 2021 | 12:28 AM
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Originally Posted by dc6902
Key resistance has been bypassed. I forget word for it.
Reason for bypass? Was something broken? Based on my 91 and others I have heard of, if it even cranks, it shouldn't be VATS although that won't stop people blaming it for the problem.

What you say it doesn't start, what do you mean EXACTGLY? Does it turn over? If so, does it try to run? Have you checked fuel pressure? Spark?
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Old Mar 14, 2021 | 07:49 AM
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Have not checked fuel pressure.
At times when you turn the key on the radio etc works but when you try to start nothing happens. Acts like a dead battery. Give it 20 minutes and it will start right up. The key wiring was done before I bought the car.
If I deprogrammed the vats that will be one thing out of the way. I don't need it.
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Old Mar 14, 2021 | 09:37 AM
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Originally Posted by dc6902
Have not checked fuel pressure.
At times when you turn the key on the radio etc works but when you try to start nothing happens. Acts like a dead battery. Give it 20 minutes and it will start right up. The key wiring was done before I bought the car.
If I deprogrammed the vats that will be one thing out of the way. I don't need it.
Put an idiot light on the exciter wire of the starter. If it gets signal, you can jump on the VATS bandwagon all day long but it will be a new starter. If you don't get signal, then you have to track backwards. Could be a problem with the neutral safety or clutch if manual, etc. Diagnose first. Fix next. Add variables or throw parts last
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Old Mar 14, 2021 | 01:22 PM
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Originally Posted by dc6902
Looking for someone to remove vats from my computer in the Houston TX area. Car is a 1994 Corvette with a obdll connector and obdl system.
Car doesn't start at times. Usually will restart in 20 min. Help me out.
Since you have a '94, you can do it yourself. Buy this cable: http://aldlcable.com/products/aldlobd2u.asp

You can then use a program called Flashhack to read the BIN from your car. Once you have your car's bin, you can use TunerPro with this XDF definition file to edit it any way you want, including disabling VATS in the PCM. Once that's done use Flashhack to flash the modified BIN back.

That said, couple of warnings.

1. If it really is a VATS issue, you may not be able to connect to the car. The car will only let you connect to it if the correct key is inserted (well, if the correct resistance is detected by the CCM). If you attempt to do flash operations while VATS is locking you out, you're going to have a bad time.

2. The core of VATS is the CCM, not the PCM, and you can only reprogram the PCM. Reprogramming the PCM to remove VATS fixes the fuel injector cutout, but it doesn't fix the fact that the CCM controls the fuel pump relay and the starter relay. These are separate issues that no amount of reflashing is going to fix.

3. Are you suuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuure it's a VATS issue?

Originally Posted by ihatebarkingdogs
I also have a resistor. I still had a VATS disable in my 90. The SECURITY light was on in RUN. I know my car well enough to immediately recognize what the problem (but not the cause) was. I waited 5 minutes, and it fired right up.

Next thing is to check for an H46 code in the engine ECM. You can do the ALDL jumper and read the service engine soon, or do the CCM diagnostics and look at Module 4.1 for an H46. 46 is "fuel-enable not received from CCM". There are also some CCM codes associated with improper resistance. I think 53.
Per https://tech.corvettecentral.com/201...trouble-codes/

51 Pass-key invalid key detection
52 Pass-key key detection circuit shorted
53 Pass-key – key detection circuit open or shorted to battery
54 FEDS fuel enable failure
61 Pass-key – key #1 programming resistance out of range
62 Pass-key – key #2 programming resistance out of range
63 Pass-key – key #2 programming resistance low

Agreed that pulling codes would help in the diagnostic process anyway.

Last edited by Nomake Wan; Mar 14, 2021 at 01:26 PM.
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Old Mar 14, 2021 | 01:38 PM
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Originally Posted by ihatebarkingdogs
I waited 5 minutes, and it fired right up.
What would have changed that it allows an attempt 20 minutes later? It should be under 5 minutes or am I mistaken?
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Old Mar 14, 2021 | 01:42 PM
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Originally Posted by aklim
What would have changed that it allows an attempt 20 minutes later? It should be under 5 minutes or am I mistaken?
I'm guessing it didn't actually take 20 minutes, but that OP simply waited 20 minutes anyway. The actual lockout period is 3 minutes (though if you perform another failed attempt during the 3 minutes, the timer resets).
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Old Mar 14, 2021 | 01:48 PM
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Originally Posted by Nomake Wan
I'm guessing it didn't actually take 20 minutes, but that OP simply waited 20 minutes anyway. The actual lockout period is 3 minutes (though if you perform another failed attempt during the 3 minutes, the timer resets).
Fair enough. I'd still like to see it fail and check if the starter is getting the signal from the "S" terminal or exciter wire or whatever it is we call it. My old starter would do that. It wasn't VATS (fully functional) but oil. Oil dripped down enough, messed up the starter so you would have to jump it if you didn't start it every couple of days. So we blame the battery until we found that it was good.
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