sean.peters

Gents - strange problem with my 2012 JK. Went to start it this morning, and the ESC and ETC lights both came on (ETC light was flashing). The Jeep runs really rough now (yesterday all was fine). Hooked up the code reader, and it's not throwing any codes. Any thoughts on why both of these indicators suddenly came on?

It's got like 50k miles, and the tires, suspension, etc, etc, is stock.

14Sport

I would start by looking at all 4 wheel sensors. See if a connector came loose or broke. Especially if it has be drooped lately.

Mark Doiron

Do you still have the stock battery? I'd have it checked. A weak battery can cause weird performance from the Jeep, including a variety of dash lights.

airborned

Mine had the same type of problem. I had to replace one of the wheel speed sensors.

Mark Doiron

Just to be clear, did you also experience "rough running"? Or maybe I'm reading something into OP's description and he actually meant the ESP was kicking in causing uncommanded braking (which I have seen wheel sensor problems cause), and not a rough running engine.

14Sport

I see what you're saying, Mark. He wasn't clear whether the engine is running rough or the Jeep is performing rough. I suspected the wheel sensors because that usually throws 2 or 3 lights up dealing with traction control. I thought the low battery threw 4 or 5 lights up but I could be wrong. Both good things to check though.

Mark Doiron

They both seem to vary in lights showing. That was why I cued in on the rough running. But it isn't clear what he meant.

sean.peters

The engine's running rough. There's no uncommanded braking that I can detect. It seems to be in the so-called "limp mode". I can't see how the wheel sensors could be the issue... the problem exists even while idling and not moving.

Thanks for the input so far.

sean.peters

Also: if the battery was the issue, wouldn't I see it in the form of it being slow to crank, etc? Nothing like that is in evidence - the Jeep cranks fine and starts right up. It just runs really poorly once it starts.

Mark Doiron

Yes you should. Hmmm.