So i got my scangauge and i P115D is the code i got for my engine light and can't be cleared. I put my intake mods in a year ago and had a brief period of my engine light. Now a year later its on not going away. I saw on another thread that this code simply means MAF too high compared to model. Any insight on what that really means, and is it causing any loss in power or is it just the car saying this isn't normal, but really has no real effect on the performance.

 

It's definitely a MAF related code. Mine goes off sometimes because of my HKS SSQV. Before I added this part I didn't have any issues with my CAI. I notice you have a BOV too. If your BOV is venting to atmosphere at really low boost pressures, the ECU will think there is a leak in the combustion air system. At higher boost levels, the diverter valve via a command from the ECU, so when you're venting to atmosphere with the BOV during high boost, there is no issue. I would try adjusting the BOV so it only vents around 8 psi or higher. Clean your MAF while you're at it too.

 

i don't know man, that BOV isn't in the most accessible spot. I was looking to get something new, looks like a boost gauge will help for this situation. I did start doing a lot more city stop and go commuter traffic in May. That could be a cause of the really low boost pressure, no? One other thing, having the BOV vent around 8 psi will do what exactly? and with out a boost gauge how the hell would i know when it's venting?

 

The problem is not that you have low boost. The MAF detects flow rates in the combustion air system and there is are known amount of air the ECU will expect to see based on the throttle input. In your situation when you're driving in stop and go traffic and get up to around 2psi of boost as you start to accelerate and then all of the sudden you lift off the throttle to stop. The ECU is expecting to BARELY open the stock diverter valve and make a steady transition in boost pressure from 2psi down to vacuum conditions again.

When you have a BOV that's venting at a low boost pressure the ECU suddenly sees a dip in boost pressure as the pressure sensor sees vacuum conditions and then having the pressure rise up again as the valve closes. To the ECU, this sudden drop in pressure is not normal during these conditions. The ECU's logic says that there must be a leak or a possible sensor defect (in this case P115D). However, when you're accelerating aggressively and shifting through gears, the ECU will expect to see a large drop in boost as the stock diverter valve opens all the way during throttle lifts.

The solution is to adjust the BOV spring so the valve doesn't open under low boost conditions. In all honesy, the BOV is really a aesthetic type of device on the R56, so if you're still having issues I would consider removing it and see if you're still having problems. I have the same issue as you and it can be especially annoying on the track. I'll gently let off the throttle in some areas of the track and hear my HKS SSQV just barely venting and then POW the code trips and I can only get like 3psi of boost. I'm thinking of getting rid of mine all together because of these annoyances. At least the Alta BOV has an adjustable spring!

The ECU's sensitivity to throwing this code seems to vary quite a bit on all R56s so try this out and report back.

 

I have a cat-less down pipe i'm holding off on installing. once installed would the blow off valve play more of a usefull role?
I know there's debate over the need for a BOV and any of it's benefits, but i figured everyone else is doing it, why not me haha
Thank you for your help

 

No it will not. Just because your turbo will spool up faster now since there is less backpressure in the exhaust, the diverter valve will still limit the amount of boost going to the intake manifold to protect the engine. I have a catless downpipe too and above anything it adds a good amount of torque and an amazing sound (subjective) to your exhaust if you have the right muffler.

From talking to other people it seems as though in '09 when the ECU was programmed to be more stringent with its engine parameters people started having more issues with aftermarket BOVs. Some people have good luck and some people have bad luck with this code.

 

This could be the solution to the P115D issues from vent to atmosphere BOVs on '09+ R56s. Don't know if testing has been done yet...

http://www.waymotorworks.com/wmw-per...off-valve.html

 

I got this code because the cold side intercooler hose blew off. Probably a rare reason for this code though.

 

Please help!

Hello NAM this is my first post, and I am in dire need of expert advice!

I have a manual, 2007 Mini Cooper S (R56), with an AEM Cold Air Intake. (link below)
http://www.outmotoring.com/aem-r56-s-intake.html

I bought the car used, and after reaching around 80,000 miles I needed a new clutch. A local autobody repair shop took a look at the car and reassured me they would be able to fix it in a few days. It took them nearly a week and a half.

After getting my car back and driving it 10-15 miles a loud banging noise began to occur when I shifted into gear and the car stopped and would no longer shift into gear or move. I had it towed back to the shop, where they told me they forgot to put back a bracket into the car's transmission and after a couple days said the car was ready to be picked up. When I turned the car on, the check engine light had appeared.

When I told them, they said it had always been on, which is NOT the case. Nevertheless, they used a scanner to find the code which was P115D (MAF code). When I drove the car, it felt sluggish and no longer drove like a mini. It felt as if I had lost boost/torque and even after flooring it, the car would not move the same as it used to. They told me they had no idea what the code could be related to and that it was not their fault. After scouring the internet I found this thread, and similar ones with this problem.

I still cannot figure out what the problem is, even now. I have checked the innercooler hose and clamps. It does not sound like there is a vacuum leak anywhere and I had the shop clean the MAF sensor. I even had a mechanic friend look at the car and he cannot figure it out. I am so upset and disappointed. I want the car to drive the way it's meant to drive. It has been about a month total time now, and my car is just sitting in their shop.

Does anyone have any suggestions?

 

any updates?