If I program VATS out on a memcal is there any way the enable start relay can still fault causing a no start condition? If so, what's the bypass around this relay?

 

if the vats is bypassed in the programing you will have injector pulse but no starter enable. jumper the 2 larger gauge wires on the enable relay usually yellow and purple or green and purple. You can also ground the relay on the lead from the pass key module. This is more of a electrical question than diy prom.

 

Thank you, after reading for about an hour I was leaning towards exactly what you said. I wasn't sure if it was still capable of fault though.
I knew I'd get the answer here!

 

By disabling VATS on the memcal all you have done is removed the requirement for the ECM to get the fuel enable signal from the VATS module.

You have changed nothing as to the module reading the key correctly or operating ( or not ) the starter relay so if any of the physical components or wiring are bad you will still have problems