29F1 Fuel Pump Plausibility

Shane303

Specialist
Nov 6, 2016
83
44
0
Mesa, Arizona
Ride
2009 E92 335i
I am getting 29F1 Fuel pump plausibility code with half engine light. (this code only)
Being unable to find much information about the code, I am hoping for some insight.

Here are some logs when the code appears. Notice how the HPFP stays high while the trims are pulling fuel. When the 29F1 code pops, it disables the HPFP. Is this a tuning thing, or am I replacing my HPFP after 20k miles?

http://datazap.me/u/skampstra/29f1?log=0&data=13-22-23
http://datazap.me/u/skampstra/29f1?log=1&data=13-22-23
http://datazap.me/u/skampstra/log-1490276462?log=0&data=13-19-20-22-23-24-25
http://datazap.me/u/skampstra/log-1490276462?log=1&data=13-22-23-24-25

***UPDATE***
It was the tune causing the 29F1 code. (Luckily)
 
Last edited:

Velocity26

Specialist
Feb 7, 2017
61
21
0
Tampa, FL
Ride
2010 335i
One thing that I love about Cobb is that you can plot the pressure requested, in addition to the rail pressure, so that you can see if the targets are being met. Honestly, your HPFP seems decent up to the point that the fault pops. I can see where you LPFP is sagging under load, but I have seen worse without popping a fault like that.
 
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Reactions: Shane303

mkster08

Corporal
Nov 5, 2016
107
19
0
Kansas
Recently my car has died on the highway very randomly ive caught it while monitoring in mhd too.. I never have any issues with wot it has Only happened a few times while cruising and lpfp and hpfp are always fine when it happens. But I'll get the fuel pump plausibility code when it dies. I have talked to a few friends who thought it could be the low pressure fuel sensor on its way out
 

mkster08

Corporal
Nov 5, 2016
107
19
0
Kansas
Wow I don't have anything like that yet I guess haha, it just pegs it high when I let off gas after a pull. During pulls I do have some fluctuation but always in good levels
 

Basinillero

New Member
Aug 29, 2018
4
0
0
Pennsylvania
Ride
2007 bmw n54
That will likely be your issue. I chased a similar problem down on a 2007 and replacing mosfets didn't resolve. @Omar@VaderSolutions sells the updated DME and was what eventually fixed the issue. 2007's are pain in the ass
Ok thanks for the info i already got my cas module out today and also took my dme out for when the new one comes in i just gotta put it in and the cas module i hope everything goes well and will update after i get the msd81 upgrade
 

doublespaces

Administrator
Oct 18, 2016
9,303
4,331
0
AZ
Ride
2009 E93 335i
Ok thanks for the info i already got my cas module out today and also took my dme out for when the new one comes in i just gotta put it in and the cas module i hope everything goes well and will update after i get the msd81 upgrade

Did you solve this? I'm actually getting this code.
 
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doublespaces

Administrator
Oct 18, 2016
9,303
4,331
0
AZ
Ride
2009 E93 335i
Anyone ever solve this same code here, with fan on high. Replaced hpfp same codes persist. New low pressure sensor and pressure sensor located on the rail is on the way.

In my testing, I am seeing a strong correlation to the temperature in the situations which cause this code to appear for me. When the car is cold, I get this code almost without failure and once its warm it will never come back. I wait to go on the freeway until it goes off otherwise my car stalls on the road, sometimes in the middle of the on ramp. In the summer months, it doesn't happen at all.
 

Jon1998

Lurker
Dec 1, 2017
19
10
0
Ride
2008 bmw 335i maxxecu
Ahh i see, Im gonna try fuel pressure sensors and then Ekp, i find it weird that the fan goes on full blast.