JHG

'08 535i with N54.
Have a fuel pump error and car goes into limp mode. How can I tell which pump is bad?
Can an in tank pump be bad but still get the correct pressure out of the HPFP to the rail at idle?
Recently, I would get the limp icon on the dash when I put my foot in it, so I figured a pump was goin bad.
It would seem, the pressure at idle with a failing pump would be irrelevant.
Thanks. Great site!

seanjordan20

You need to look at the live data for your fuel pumps to know which one is bad. More than likely it's the HPFP. Your code also should point to the right one if using a BMW code reader

JHG

Update. I had both pumps so I replaced the HPFP and all was well.

seanjordan20

What was the outcome. Where you able to look at the live data (psi).

JHG

No. At time I didn't have software. Now I do but it's in German....working on that.

habbyguy

This is where I use the Google translate app - just point my smartphone camera at the screen and tell it to translate German to English. Not always a perfect translation, but almost always enough to decipher the meaning.