P1631 and VATS

[caniggia]

We have problem with 4.8 Silverado, starts and stop, effect like immobiliser not working, we get "P1631 Theft deterent password incorrect" often.
Does disabling VATS or/and this code in tune will disable immobiliser and alow car to start?

VATS is set to serial in this car.

If there is any chance is helps, we try, otherwise it will be coin lost.

Thanks.

[SSUte01]

We have problem with 4.8 Silverado, starts and stop, effect like immobiliser not working, we get "P1631 Theft deterent password incorrect" often.
Does disabling VATS or/and this code in tune will disable immobiliser and alow car to start?

VATS is set to serial in this car.

If there is any chance is helps, we try, otherwise it will be coin lost.

Thanks.

Try a VATS re-link!

[caniggia]

How to?
We tried some pin relearn procedure with some kind triple 11minutes ignition switching, but no luck.
Owner also tried some resistance emulator for key, but also no luck.
Car stopped on normal driving on highway and since won't start.

[flame]

If the engine is running the vats fault won't turn the engine off. It will turn on the security light and will not start the next time. Easy test would be to just set it to vats none. What vehicle?

[caniggia]

If i know it will help, i'll try, i'm asking before buying credit.
Security lamp is on. It's 2001 i think, Silverado.

[flame]

http://www.cadillacforums.com/forums...ypass-how.html

[caniggia]

Hi, this is what they already tried without success, looks it's problem with security between pcm and bcm, they dont speak together correctly, and i dont know if disabling vats or error will disable pcm with bcm speaking in this case.
Finally i'll try it probably if customer agree to take risk.

[flame]

yes turning vats off will get rid of the fuelcut

[SSUte01]

The only time I have come across P1631 is when I have re-tuned cars in the past where a lazy tuner has simply completed a 'Write Entire' with a similar tune from their library and the VIN/OS isn't the same as original. When I restore the VIN/OS initially, I often run into the P1631 (sometimes 1626/1630 aswell). I've found a VATS re-link as per the software help works or if you can't be arsed or time limited, setting P1631 to 3 - No Error Reported will cure it. It frustrates me when I come across tunes like this and it happens more often than not. Setting VATS to None won't eliminate the P1631

[caniggia]

Great to here, now it's worth to try.
I'll let You know results.

[caniggia]

After switching off car is starting and running for about 30 sec and then burning ecu fuse. So looks there is some electrical problem. Btw, after switching vats and this error security lamp is blinking still.

[flame]

Blinking security light is normal if it is on solid then you have a problem. Sounds by the fuse blowing that vats is not your issue anyway.

[caniggia]

You are probably right, now I'll start searching, but I think it can be 3rd party ECU from propane installation.

[caniggia]

Finally I found issue, it was fuel pump that was burning fuse.
Now car is running OK, but VATS had to be disabled, there is something wrong with one.

Is there way to get of blinking security message?

[flame]

No the security light is controled by the body computer