[bizzleb109]

As the above title mentions can anyone give me a heads up please im getting error code 0029F1??

Pls help

Thanls

[gbalthrop]

That fault indicates the signal from ONE of the TWO fuel pressure sensors on your N54 Engine (either High Pressure or Low Pressure, probably the former) is NOT within proper range, therefore IMPLAUSIBLE. That could mean it's reading too high, too low, or NO signal at all. That could be anything from a disconnected sensor (anyone worked under the hood recently?) loose connection, wiring fault, bad sensor, or an issue with either the Low Pressure Pump (LPFP) in the tank, or with the HPFP (High Pressure Fuel Pump).

What Scan Tool or Software was used to read that code, and WHAT MODULE was it found in (MSD80 I presume)?
Were there any other codes in either the DME or the EKP (Fuel Pump Module)?
At what mileage/km was the code saved (FF Data)?
Do you have a Scan Tool or Software such as INPA/ISTA?
What if any performance issues or symptoms are you having?
What warning lights or icons are lit on the Instrument Cluster?
Who read that code & why?

If you are able & willing to diagnose the issue yourself with help from the forum let us know. Otherwise you need to see a shop with proper diagnostic equipment.

Here are the relevant TIS circuit diagrams for the two sensors (B2261 High Pressure or Rail Sensor, & B6125 Low Pressure Fuel System Sensor), along with Installation Location for each:
https://www.newtis.info/tisv2/a/en/e...system/xFCjesC
https://www.newtis.info/tisv2/a/en/e...sensor/SCO2U5k
https://www.newtis.info/tisv2/a/en/e...ystem/DjYjknre
https://www.newtis.info/tisv2/a/en/e93-335i-cab/SCGgj8M

Please let us know what you find,
George

[Vania335i]

Hi... if there is no driveability issues with your car and that code is the only one stored in your dme then clear it and ignore it... that code alone does not.mean an actual fault unless its associated with other fuel system faults... even bmw tells its services to ignore it unless there are driveability issues... good luck

[roadkillrob]

I had this a few years back (2008) ended up replacing the high pressure fuel pump sensor, it is under the manifold, but manifold doesn't need to come off, just the airbox and could get to it. The early sensor had issues from vibration and would eventually fail as they were in a hard line, you can either just replace the sensor for like 50 bucks or do the new line with sensor for 180. It probably is under 2 hours to do the job if that is what it is.

[newsimplegroup]

I had VANOS solenoid failure - and now I have this problem with significant reduction in fuel economy and throttle under boost. Around 1-3 RPM, I have to push the pedal further towards the ground to feel acceleration. The turbos work fine, the VANOS solenoids were replaced, and now I dont know where to begin. I had a shop order the HPFP for me.. but now Im worried I made the wrong call. They are useless for some odd reason.

[bizzleb109]

I took it in to my local garage we could not chat for long but he mentioned the high pressure fuel pump. What other symptoms would indicate hogh pressure fuel pump, as I was thinking more in the line of low pressure fuel pump? Also whilst in the process was rhinking of changing my breather hoses can anyone tell me what diameter and length I should get pls?

[bizzleb109]

To read the codes I used the Carly app

[IllSic_Design]

Originally Posted by Vania335i

Hi... if there is no driveability issues with your car and that code is the only one stored in your dme then clear it and ignore it... that code alone does not.mean an actual fault unless its associated with other fuel system faults... even bmw tells its services to ignore it unless there are driveability issues... good luck

+1. I have this code even with upgraded lpfp, new lpfp sensor, and a new hpfp.

[newsimplegroup]

Wow Illsyc..

I just had Vanos failure. Ended up doing plugs, VANOS Solenoids, Water Pump, Fuel Pressure regulator.

I have a loss of power.. stuttering/feels like misfire at low RPM..

Fuel Pressure plausibility. Im losing pressure. I cant fucking figure it out

[mikejones9547]

hoping someone sees this post i have an issue with my lpfp pressure ive changed fuel pump once out of a known working car (my other e92) ive also changed the regulator when i cold start the car i have around 67 psi of lpfp pressure but as the car warms up the pressure dips gradually till it gets in the 50s i have a lpfp sensor on the way just hoping someone has ran into this issue before or has had similar issues or has ideas really frustrating and want to get this taken care of thanks for any and all recomendations

[lowrydr310]

Originally Posted by mikejones9547

hoping someone sees this post i have an issue with my lpfp pressure ive changed fuel pump once out of a known working car (my other e92) ive also changed the regulator when i cold start the car i have around 67 psi of lpfp pressure but as the car warms up the pressure dips gradually till it gets in the 50s i have a lpfp sensor on the way just hoping someone has ran into this issue before or has had similar issues or has ideas really frustrating and want to get this taken care of thanks for any and all recomendations

There are a bunch of posts with similar stuff. Usually the new LPFP or sensor fixes the issue, but in some of the cases people found a disconnected line at the sending unit inside the left side of the tank, or even a kinked fuel line in the tank or even outside going from the tank up to the HPFP.