E53 3.0 crank, no start and my wits end

[Henn28]

Originally Posted by Effduration

Welcome.

FPR is Fuel Pressure regulator...I believe it is part of the fuel filter on the E53.

I happen to think all your issues stem from the parasitic drain that I don't think you have properly diagnosed and solved.. I am working on one myself at moment.

These cars really don't like low voltage and it leads to all sorts of warnings and strange behavior.



Using a multimeter set on the 10amp setting on the negative battery cable, you need to see amperage in sleep mode at 50 milliamps or less (= 0.050 amps). It is not enough to watch amperage drop when it goes to sleep mode. This is summary of the testing process..search on it...

You then need to test fuses measuring millivolts (not milliamps) to try and determine which circuit is causing the problem. There are several good videos on this...It may be your FSU, radio, any aftermarket electrical component, or something else.

Hopefully, A fully charged battery, fixing the parasitic drain and an EWS re-synch willl solve this.. But honestly, after that I think I would find a good non-dealer BMW specialist and let him/her fix it.

+1. Some e53s don’t have FPRs (mine is a 2002 and has the smaller filter without one), but most have a larger filter with the FPR sitting on the output end. I believe it can be bought separately.

Low batteries can cause all sorts of seemingly unrelated issues.

Make sure the car goes to sleep…16 min is advertised time for all systems to power down. Bridge the negative at the battery, or just upstream where it goes to the chassis by the fuseable link block behind the left rear seat. Best case is you secure the meter leads, position the meter where you can read it thru a window and shut and lock the car. Hack your watch and wait. The amps may drop off in a couple increments as systems go to sleep, but at 16-ish min you should see the meter drop to .05. Mine fluctuated between .04 and .06. If it doesn’t then you need to pull a likely culprit fuse and do the whole thing again…and rinse/repeat as many times as necessary until you find the draw.