[hdpu]

Hi Guys,
my old E91/2009 engine does not work any more:
-when turning on the key, press start botton, nothing happens, like died
-there is a yellow engine symbol
-in the past days, i only replace one ignition coil.
-battery seems fine, 11.6v
-no special code given from OED reading (i do not have a bimmer code reader)

[hdpu]

any advice or clue about the possible reason?
if sometihng wrong with engine starter, there should be codes there, unfortunately i have not seen anything...

[Grease23]

11.6 volts on the battery is not fine. Especially if fully charged and just sitting there.

[gbalthrop]

Originally Posted by hdpu

any advice or clue about the possible reason?
if sometihng wrong with engine starter, there should be codes there, unfortunately i have not seen anything...

The CAS Fault Code, "A0B4", means there is NO engine rotation (RPM) or Starter Cranking when the START button is pressed with foot on brake/clutch. You already knew that, but if that is your ONLY CAS fault code, then the "KL50" Start signal is being sent by CAS to the Starter Solenoid.

Your "OBD Module Voltage" is only 11.5V. That is NOT sufficient to crank the Starter. There may be other issues, so please provide specific data as requested.

If you have a Multimeter, please test battery voltage at the Jumpstart Terminals under the hood. If LESS than 12.0 Volts, charge the battery. Also use a Booster or Jumpstart (at terminals under hood, NOT at battery in trunk) to see if starter activates. If you hear ANY "Click" when START button is pressed (AFTER charging battery), please identify WHERE the click comes from: JB fuse Panel under glovebox, CAS Module under steering wheel, or Starter Solenoid under rear of intake manifold.

You also have one or more "CC-ID" codes, as indicated by the "!" in the orange triangle in lower Instrument Cluster display, next to mileage/km. Use the "Check Control" procedure in your Owner's Manual to view all "CC-ID" codes. If NO Owner's Manual, you can download a pdf duplicate at this site:
https://www.bmwusa.com/owners-manuals.html
George

When you post back, please provide LAST-7 CHARACTERS of VIN.
George

[Hoody007]

I’d check the battery. Given your codes however I’d suspect the starter. Do you hear a faint click when attempting to start the car?

If it is the starter, go with a Valeo brand one. It’s what BMW now uses.