Since getting our first JK almost 7 years ago, I have seen a lot of different check engine codes. Typically, they would start off with the capital letter "P" and then followed with a series of 4 numerical digits. For instance, if you had an exhaust leak, you would get a code that looked like this, P0430. Or, if you had a cylinder 6 misfire, you would get a code that looked like this, P0306. Well, over the weekend, I finally got a code that kind of surprised me being that it contained 2 of what looked like the lower case letter "d". Specifically, the code I got was P06dd and it was triggered soon after I experienced a sudden inability to accelerate above 3,000-3,500 RPM's. When I first experienced this problem, I was just trying to get on the interstate and get up to highway speeds quickly. When my transmission dropped a gear to get there, the RPM's went up and just as I got to about 3,500, power from the motor simply cut out. If you've ever driven a manual transmission and accidentally tried shifting from 6th gear doing 75 MPH into 1st, that's exactly what it felt like. It was as if a governor kicked in and while I was still moving forward, kind of, the motor was unwilling to give me anything more. Not sure what was going on, I pulled over to the side of the road, turned off the engine, turned it back on and then started on our way again. For a brief period of time, things were back to normal and stayed that way until I tried passing a truck on a hill. When I did that, the same thing happened again. Still not sure what was going on, it did become clear that so long as I kept the motor from running up and above 3,500 RPM's, everything worked okay. And, being that you really don't need to get up into the higher RPM range to drive from point A to point B, I decided to just keep moving on but at a much more conservative pace.
Before heading back for home, Cindy started to do some research and found that a P06dd is a code that is thrown when your oil pressure is too low. Of course, this seemed odd to me be being that I had just done an oil change a few weeks back and even if it were true, I would have thought that an idiot light would have come on to let me know as much. Still, it was all I had to go on and so I decided to start with the obvious - check the oil. And, after pulling out the dip stick, it became clear, that was low... VERY LOW. When all was said and done, I ended up pouring about 4 quarts back in!! While I was glad to know that my engine is smart enough to try and preserve itself, I have to say that it frustrates me to no end that the idiot light never came on. I mean, does it only go off when it's too late? Seriously, if Cindy and I didn't have the means and the know how to look up codes, nothing short of a trip to the dealership would have gotten this easy to fix and critical problem solved.
Long story short, if you're planning on doing a ton of hard and fast driving in the desert for weeks on end, do yourself a favor and keep an eye on your fluids. And, if you ever get a check engine P06dd code, you'll now know what it is and what you'll need to do.