99 Old 3.8 P04. No crank, no start. We could jump the starter and it would run for a few seconds. Found bad ECM. Installed new ECM. Same issue, but now we have ECM communication.

Now dealing with the VATS. WE have switched the tune from Serial to PWM, changed all DTC(1626,1629,1630,1631) to "no Error reported" and tried both the SES on/off options. Have tried write, write VATS, Complete. We have tried all 4 selections of the DTC selections.

Switching from Serial to PWM will allow it to crank and run, but it dies after 4 seconds.

I've read this thread until my eyes bled. https://forum.hptuners.com/showthrea...highlight=VATS

We tried every combination I can think of, and it seems like this is a common issue that has been going on in the forum for over a decade.

Open to any and all ideas including physical bypass. A new ignition cylinder was installed with no effect. The key is a non chip style.

Tune file attached.Paul Sisco Olds.hpt