One morning last week I started my 2011 JK (102,000 miles), that I bought 6 months ago, letting it warm up. I noticed the Electronic Throttle Control light and the Traction Control lights were on and the idle was rough. I shut it off and took the Grand Cherokee to work. I started it again that evening and about 5 minutes into the idle, did the same thing. So I shut it off for a couple seconds and restarted it. Took it for a drive to see what would happen. The lights didn’t come back on while it was under driving conditions, only happened when it was idling. After a couple days of online research (a huge thank you to the JK owners on this forum) I saw that this issue was somewhat common, but no definite or quick fixes. I thought I’d start easy and progress to the more advanced repairs, if needed. I started by looking and listening for a vacuum leak, didn’t see any vacuum lines unhooked, but I thought I could hear a slight “sucking” noise somewhere. Next, I unhooked the battery for 30 minutes or so. Reconnected the battery, started it up, let it idle. Lights came on again. I read that it could be a wide variety of things, ETC sensor, dirty ETC, coolant sensors, throttle control wiring harness, accelerator sensor, PCV valve, plugs, wires, thermostat, etc. I couldn’t find a definite answer anywhere. I figured I’d start simple and try replacing the PCV valve. I wanted to replace it anyway, especially since it was using about a quart of oil every 1,500 miles. Apparently and thankfully, the new PCV valve solved my issue! I replaced it yesterday, went for a test drive, and it “seemed” to run better. Let it cool down overnight, started it this morning and let it idle for 20 minutes, no lights! So, if anyone has the ETC and TC lights suddenly come on, I’d suggest replacing the $11 PCV valve first and see if that might resolve the issue. So far it has for me (fingers crossed).