2012 R60 S with throw these codes on start up once in awhile. Check engine comes on but after drive, shut off and restart light goes out. Then couple days later will happen again. Sometimes there is a small studder. Sometimes nothing at all. These codes seam to conflict. One is fuel pressure briefly too high and the other is fuel pressure drop below minimum. Anyone know what could be causing these codes? Thanks

 

I just got a used mini cooper S and i getting this code along with P0087.

 

I still have not figured out what it is. I cleared all codes and I am still getting P306c. Is starting to show the code more often.

 

They're all to do with fuel supply/pressure issues. Perhaps your HPFP is failing? (extended warranty on this part), fuel rail sensor failing?

 

I didn't think it was the HPFP because everything I have read it fails by not giving enough pressure but maybe mine could be the opposite? I will look more into the sensor. Thanks for the idea. Car runs fine so far just that damn check engine light. I'm wondering if me changing out the thermostat has anything to do with it. It started giving this code right after. The HPFP is right there and I'm wondering if there is an adjustment on it? Or maybe just bumping it while I was working?

 

R60abq, I'm having the same issue. I suspect the HPFP, but don't want to make the 5 hour round trip drive to the closest dealership for a warranty replacement just be told it's a sensor I could have fixed at my local shop. What did your issue end up being?

 

I never figured out what it was. We traded it in. Sorry I couldn't help. I remember how frustrating it was. I always thought it was the HPFP but thats just a guess. Good luck.

 

I had the P306C and P0087 codes with an occasional CEL on my 2012 R60S....Also very intermittent stuttering and when the CEL was on performance was definitely lagging. Took to my local repair shop and they pulled multiple BMW codes that my OBD reader didn't show (2CO1, 2F7C, 2F77, 2BDD, 32E3 and 2F76). They diagnosed bad High Pressure Fuel Pump (HPFP) and recommended I go to the dealer as it's under extended warranty. Dealer couldn't duplicate the problem initially but found HPFP leaking from the temp compensator. In addition they found a leak in the water pump so they replaced both components, both under extended warranty. Note: My warranty is completely expired, both items have had the warranty extended by MINI USA. If I had to pay for them the HPFP was $1800 and the water pump was $900 (parts only).

Hope this helps!

Pete

 

Mine ended up being the HPFP as we all suspected. I eventually took it to the dealership several hours away, and left it with them while I was away on a trip so it wasn't an inconvenience. They replaced it on the extended warranty, so parts and labor were covered.

While working on this problem I checked several other issues. In some cases I thought they may be related to the codes, in other cases I just wanted to check in case it was work I'd need done at the dealer while it was there for the HPFP. The timing chain and guides were fine, but at 70k miles I replaced the tensioner anyway. The intake valves were actually clean, although it seems they often need walnut blasting by 70k. The spark plugs were shot and were replaced, but that had not effect on the codes that kept coming back.

Other codes I had with my HPFP issue:
P0087 Fuel Rail/System Pressure - too low
P0300 Random/Multiple cylinder misfire detected
P0301 Cylinder 1 misfire detected
P0302 Cylinder 2 misfire detected
P0303 Cylinder 3 misfire detected
P0304 Cylinder 4 misfire detected
P0306C
P10EE
P15DF