Has anyone had any dealings with this code? Car didn’t pass smog. Thanks in advance

I think that's a typo or your scanner has an issue. The FSM dbase shows no codes on an '06 M which have a P3 prefix.

Looks like my reply didnt post, I dont know why you assumed it was for an 06 car but it is a 2013 m35h. Not a typo, any actual help is appreciated though.

That's what's listed on your side panel, 2006 M35. I'll look it up later for your '13 h and let you know.

P30EF is a Li-ion battery problem. There are either one or more worn-out cells with high internal resistance, or there's a resistance problem in the harness the LBC uses to measure them. The DTC diagnosis basically consists of disabling the high voltage and ohming the harness, if the wires for all 96 cells show no resistance issues then the battery is shot.

I hope it’s a fix and not a replace, just weird to me that a battery code would prevent the car from passing smog. Any advice on replacing the current hybrid battery with a used one? Worth it to save a couple bucks?

If you're in Cali then my understanding is that any code in the engine or drivetrain will flunk the car, whether it has any direct effect on emissions or not. In this case it makes your car run on the gas engine when the electric could be helping, so I guess that makes half-a$$ sense.

Used LB's are always a crapshoot. If you go that route, make sure it's returnable.