Recently my 2012 JKUR started misfiring on multiple cylinders. The check engine light and battery light had been on for a while.

The battery and alternator have been replaced since the battery light has been on, they did not fix the issue.

I have replaced the crankshaft and camshaft sensors, the #3 cylinder plug and coil have been replaced several times, the passenger side head has been replaced years ago, and the passenger lifters were replaced a few years ago.

The following codes are showing on my code reader. P0300, P0303 (intermittent for most to the life of the Jeep), P0013, P2172, C1405, U0125, C121C, C2114, P0622.

I am thinking either I have a short, a ground or the ECM is bad. I have been trying to get it to a shop, but everything is booked up for weeks. I am about to just take it to the dealer, but figured I'd throw it out to the interwebs and see if anyone has some ideas.

 

In many instances the multiple codes are related to the same cause, Not to question have you researched all the codes for possible causes and is there a common re-occurring cause. With the current situation with the CDK hack many dealerships bus. opn system is down and cannot print invoices so check to see if that dealership is fully operational.

 

The ECU is what keeps coming up. Which is what leads me to believe that it's a short, a ground or the ECU is bad.

 

Dealer says the intake melted from the inside on cylinder 3 and one valve is not opening. Said it's the worst he's ever seen.the intake melted from the inside on cyl 3 and one valve not opening. he needs to tear down more of the engine So far he found one of the valve stems broken off and the head cracked where the valve guide is. one of the rockers had fallen off and the roller for it is completely missing, but the oil is full of metal. probably from the engine chewing up that roller.