When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Any suggestions on where to send my 1995 LT1 ecm to be reprogrammed to have the vats deleted will be much appreciated.
I live in northern NJ.
vin 1G1YY22P5S5117119
after 35 years, not so easy to locate
thanks!
Resistor bypass installed; however, too often
(once or twice a month),
SECURITY still light remains lit,
with consequent starting disabled;
hence, stranding me.
Resistor bypass installed; however, too often
(once or twice a month),
SECURITY still light remains lit,
with consequent starting disabled;
hence, stranding me.
On my 1988 and 1989 the root cause ending up being the start enable relay. A key bypass only eliminates an issue with poor contacts between a resistor key and the key cylinder.
I'm in Staten Island. You can ship it or bring the ECM here if you want and I will flash it whle you wait. I have a bench harness and dont need the car. PM me to exchange contact info.
Pulled this from my 1996 Service Manual. It looks like GM changed the name of this relay to Theft Deterrent Relay. Even if you disabled VATS in the ECM, isn't this relay still in play? Others with more expertise would need to comment. My understanding of VATS is that there are 3 main areas of failure; key resistor contacts (which you bypassed), the controller (specific match to key resistance) and the relay that the controller enables. Wondering if the newer C4s eliminated the controller and is now part of the ECM.
Pulled this from my 1996 Service Manual. It looks like GM changed the name of this relay to Theft Deterrent Relay. Even if you disabled VATS in the ECM, isn't this relay still in play? Others with more expertise would need to comment. My understanding of VATS is that there are 3 main areas of failure; key resistor contacts (which you bypassed), the controller (specific match to key resistance) and the relay that the controller enables. Wondering if the newer C4s eliminated the controller and is now part of the ECM.
There have been several posts over the last few months about VATS specifically in 90-96 cars. Deleting it out of the ECM does not solve 100% what the OP wants to do. The ECM and CCM do multiple communication handshakes about VATS to allow the car to start.
Which is why I asked, what is he doing about it in the CCM.
The system works. You just have to understand how it works. Understand how to diagnose, And then you can fix it.
Still researching the issues. The 16181333 ECM can program the $EE Definition File
via the 16 pin ALDL OBD 1.5 port which can disable VATS and prevent fuel cutoff;
but will it also solve VATS shutting down starter relay?
UPDATE:
I got a resistor pack with values explicitly for VATS.
I did use a multi-meter to pick out the most accurate resistor,
to replace the resistor combination kludge I had taped up,
and now with a more exact resistor I have not had any more problems.
I did buy the 555 IC to have in case it comes to that.
I also bought TunerCAT since the 94 and 95 computers are electrically programmable to delete VATS.
Cheers!
Last edited by GraphMan; Jul 28, 2025 at 08:47 PM.
ecm vats delete reprogrammer suggestions plz?
