engine still runs with key out...TST still lit
 

I just put the 2500 back on the road yesterday and it started on the first click...but the tst power number on the r39 has been flashing and when I turn the key off the truck keeps running and the tst is still lit up. Am I getting some stray voltage from somewhere to keep the tst on and keeping the ECM going with the key off...to power down the truck I have to pull the plug on the tst...anyone have this problem....should I switch the fuse tap for the TST. Help as I'm on the road. Kerry

Sounds like your getting constant 12v i'd check the fuse # you have it hooked to an see if it has constant power or just with ignition. I have seen a r47 with cooldown feature turn itself on an powerlevel go up but not the r39.