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Bmxlee Bmxlee is offline
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Posts: 29
Join Date: Mar 2017
Car: E92 335i
Default Reduced power warning, 30fe code, and a glitch JB4 - 03-15-2017, 05:02 PM

Hey everyone, this is my first post.

I have a 2008 335i which has done roughly 55,000 miles.

A few months ago I fitted a Jb4 G5. The install was very simple and all went smoothly. The car felt amazing and wheel span at every opportunity.

one day (about a week or so ago) I was driving to work and decided to check which map I was using (I often switch between map 1 and map 5, but I still cant tell a difference). when I exited out of the JB4 menu the tachometer was stuck in its current state and would not move. I played about with it entering and exiting the menu and eventually it went back to normal and was moving. About 5 minutes later I had the dreaded "engine fault, reduced power!" come up on the idrive. I did my work shift, got back in the car and noticed it was gone. I drove back home and all was as normal again.

Eventually it happened again and became more frequent, usually when in sport mode at high RPMs. Its now gotten to the point where it happens everyday too and from work. sometimes i'll switch the car off at a set of traffic lights to clear the code but it shortly comes back again a few yards up the road.

Today I bypassed the JB4 (map 0) and the problem still happened, This time in drive mode at low RPM (about 1500-2000)


INPA has shown a few codes, one in particular is the 30fe (over boost) code.

I was also suspect that the HPFP was on its way out as it has been taking longer to start the engine recently, not by much though. But sometimes its starts quickly.

I've checked all the vacuum lines and they all seem fine.

I recently installed VRSF down ***** and took the opportunity to inspect the wastegates whilst they were exposed and they also seemed fine.

Bmw tells me that its had recall work done on the injectors so we can rule that out. They also denied any knowledge of the HPFP warranty.

I will clean the Tmap sensor possibly tomorrow and try to inspect the wastegate solenoids but apart from that im fresh out of ideas. The glitchy JB4 I find peculiar.
I'm hoping Terry from BMS can chime in on this.

I should probably add that the problems came about a few days after doing the Aplina flash. Has anyone else ad issues with this mod?

The car is running Jb4 g5, VRSF down *****, K&N panel filter, and Alpina B3 Transmission flash.

I plan on fitting a new chargepipe, diverter valves and BMS DCI at the end of the month.

Any ideas?

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