LS swappers VATS question
Thread Starter
Racer
Joined: Feb 2008
Posts: 427
Likes: 32
From: North Alabama
St. Jude Donor '24-'26
LS swappers VATS question
I've got an issue with the ECM and I think its the VATS. Modified the wire harness and removed all the un-neccesary wiring like body control and using just a standard ignition switch. Everything I need is hooked up. She will turnover, but will quickly die as if the VATS is triggering, so here's the question:
Using either HPTuners or GM Tech2 is there a way to bypass or kill the VATS? Do I have to buy a license?
BTW, its a 99 Vette ECM for an LS1. And, when I hook up the GM Tech2 it says "communication failed, ensure ignition switch is on". Ideas?
Using either HPTuners or GM Tech2 is there a way to bypass or kill the VATS? Do I have to buy a license?
BTW, its a 99 Vette ECM for an LS1. And, when I hook up the GM Tech2 it says "communication failed, ensure ignition switch is on". Ideas?
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
The VATS "OK" signal comes from the BCM. You can just program it out of the PCM using editing software such as HPTuners. The TechII can't do it. With HPTuners, I can set my VATS to serial, PWM or None. And yes, you will need a licensed copy of HPtuners, either specific to your PCM or the year of car your PCM came.
Safety Car
Joined: Aug 2001
Posts: 4,883
Likes: 11
From: North Easton Mass
You can also buy a VATS bypass module if you want to keep the security feature. I have mine connected to a plug so if I feel the need I can unplug the module and know that no one is going to drive away in the car.
Rick B.
Rick B.
Thread Starter
Racer
Joined: Feb 2008
Posts: 427
Likes: 32
From: North Alabama
St. Jude Donor '24-'26
Thanks for the help guys.
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
Be careful of that one. The VATS is accomplished either by the BCM communicating serially with the PCM or by the BCM sending a frequency to the PCM. The VATS bypass modules I've seen provide either a 5V, 50Hz or 5V, 30Hz signal to the PCM. I have not seen a serial comms VATS bypass module so if your PCM is set to serial for the VATS then the module won't help.
At any rate, you'll likely need to change some other things in the PCM to eliminate the CEL and make it run as well as possible so disabling the VATS at the same time isn't a big deal.
At any rate, you'll likely need to change some other things in the PCM to eliminate the CEL and make it run as well as possible so disabling the VATS at the same time isn't a big deal.
