joegr
Dedicated LVC Member
The LS tends to bite a lot of new owners who do not know the vehicle well; its complexity and its parts expense.
Some of the electronic modules may be diode protected from both reverse voltage and spikes. But the only way of knowing is to put a full scanner in there and see what the faults are.
I’m also wondering if this vehicle even cranked over with the battery reversed. I can see a reverse voltage would turn the starter in the reverse direction and although the solenoid would have thrown the starter drive gear into the flywheel, most starters have an overrunning clutch that would not allow the starter to move the motor.
I don't think that it's possible to activate the starter relay with the battery connected backwards. I think that the PATS has to be functional to activate the starter relay, and it wouldn't be if the battery were backwards.