I'm a little at a loss on what to do next so I am coming here for an opinion before taking it to a mechanic. To give a little background we have a 2012 base countryman with 91,000 miles and have had the CEL on for a few months now. I got the codes read at both Autozone and Advance and they came back with P0128 (low coolant temperature) and P0300/0303/0304 (misfires). I knew the thermostat needed to be replaced due to the dealership recommendation from the last time we were there in March. They quoted around $700 I believe to change it. I bought one from Rock Auto and did it myself instead of bringing it to them. Also bought new spark plugs (NGK 95770) and ignition coils and replaced them. When changing the plugs I noticed oil in the spark plug tube, so I bought a new valve cover gasket and replaced it also.

So after doing all that I still have the came codes coming up using the Autozone scanner. I don't have a BMW scanner or know anyone with one so I'm not sure if there are more codes there that are not popping up. I was able to get into the "secret" OBD menu on the tachometer and under menu 14.01 it does show ERR01, which I am assuming relates to the CEL. It show A559 h and then a long combo of numbers and letters underneath. I have attached the photo here.



I've tried to look up this A559 code and I've seen a few things related to BMW cars and battery. My battery is still the original (6 yrs old now). I had it tested at Advance and they stated it was still in the OK range. I have had the Increased battery Discharge message pop up a few times also. But the car starts off right every time. I guess what I'm asking is if the battery could be too weak and cause the problems with the thermostat possibly not closing? I know the thermostat is not closing because using the "secret" menu, the engine temps never get over the 65 deg C range when it should be near 100 deg C. I beleive the thermostat not closing is the whole crux of my problem. The engine is trying to compensate and is running too rich and causing the misfires. This is also causing my gas mileage to go down.

My other thoughts are possibly the DME not sending the message correctly to the thermostat. Or maybe the DME relay in the engine fuse box not properly working and causing problems with it. Just looking for anyones opinion. I will ask around and see if anyone I know has a good scanner to read more codes than Autozone can read.

Thanks for anyone who read all that has any ideas.

 

So I had the battery tested again yesterday at Napa and their machine showed that it needed to be charged before it could be tested. This was while the car was running. So being a 6 year old battery, I just went ahead bought a new one. I also borrowed the battery tool to register the battery with the computer for the IBS system. Brought it all home and put new battery in (after cracking the passenger side cowl taking the old one out ). Started it up and the CEL was still on. I then reset the whole system through that ODB menu on the tach and it went off.

I'll try it again today to see if it's off permanently or if the menu just reset and it pops back up. I read somewhere on here that it takes 5 restarts to clear the system. Crossing my fingers that this was the problem the whole time.

 

Hope it works. Where did you borrow the battery tool from?

 

 

What battery tool is this?

 

 

I replaced the battery in our Mini and nothing special was needed. Just the standard 10mm for the top posts and whatever the hold down bolt was (13mm I think?)