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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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
 

Velocity26

Specialist
Feb 7, 2017
61
21
0
Tampa, FL
Ride
2010 335i
I have talked to a few friends who thought it could be the low pressure fuel sensor on its way out

I had that too, it was the sensor going out, but I would see the "lie detector" LPFP pressure spikes where it was going up and down wildly ... say 25 to 100 psi and back several times a second.
 

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
Im having the same issue and fault as shane 303 and i think its tune related can you tell me what was the issues within the tune that caused the fuel pump plausibility.
Thanks
 

R.G.

Lieutenant
Nov 17, 2016
669
325
0
Henderson, NV
Ride
E92 335, F10 M5
Who is jake H and chris im having the same issue and fault code as you fuel pump plausibility.

His tuner

Are you able to log? Same issue? So, start car, fuel trims pegging negative, then HPFP shuts down?

You're going to have to post more info if you need help
 

Basinillero

New Member
Aug 29, 2018
4
0
0
Pennsylvania
Ride
2007 bmw n54
His tuner

Are you able to log? Same issue? So, start car, fuel trims pegging negative, then HPFP shuts down?

You're going to have to post more info if you need help
Ok i will as soon as i fix my mosfet issues my dme just took a crap yesterday lol one problem after another
 

R.G.

Lieutenant
Nov 17, 2016
669
325
0
Henderson, NV
Ride
E92 335, F10 M5
Ok i will as soon as i fix my mosfet issues my dme just took a crap yesterday lol one problem after another

That will likely be your issue. I chased a similar problem down on a 2007 and replacing mosfets didn't resolve. @[email protected] sells the updated DME and was what eventually fixed the issue. 2007's are pain in the ass
 

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. @[email protected] 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

General of the Army
Oct 18, 2016
8,940
4,145
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

General of the Army
Oct 18, 2016
8,940
4,145
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
15
4
0
Ahh i see, Im gonna try fuel pressure sensors and then Ekp, i find it weird that the fan goes on full blast.