car wont crank over, engine immobilizer

What work was performed last?

Just saw you were looking at misfires. Plenums removed? If you had either one of the plastic coated nuts on the positive cables (one next to bank 2 ionic sensor, one in center of 'V' just above starter), chances are one isn't tight enough. Works great cold, but positive temperature coefficient of resistance with copper working against you. Increase in heat means increase in resistange = voltage drop over connection and less/no voltage to starter.

what if i check the voltage at the front of the car and its good, will that tell me if its tight? because im more than sure i tightened that well and that was over maybe a week and a half to 2 weeks ago.

The point you need to measure (the only one that ultimately matters) is the point where the positive cable drops down from the wiring harness housing to the starter solenoid. This has to be measured under load as the voltage here will be dependent on the resistance from this point to the battery pos terminal and the current flow. At low current flow, the voltage will be higher than on a starting attempt. You need to watch the voltage (if you have choice, it's easier to see on an analog voltmeter) while someone pushes the start button.

I have helped a fellow forum member here with a car which drive fine for two weeks then after sitting for a few days, refused to start. The plastic cap nut was semi-tight, but after chasing it down and even just making as hand tight as it would go, the car started right up.

BTW, the same error code was present from CAS. Monitoring the CAS analog voltage and current values in INPA, we figured it it when the voltage and current looked funky during a start attempt. EDIABAS/INPA weren't quick enough to give an accurate reading, so we popped off the bank 2 plenum and viola.

ok i just went out and check the plastic cap, it was as tight as i can go , still nothing. but i think your right. when i push the start it sounds as if the starter is trying to move but its either stuck or just weak. i cant jack the car and go under since its on the road to check the voltage at the starter, is there anywhere else i can check from the top, a picture would be extremely helpful if you have access to one, thanks

PM sent

I think align the Dme/cas.

Jim may have said this already

2009 BMW X5 35D won't crank or start

I have a 2009 BMW X5 35D. We drove it fine and was able to come back home. However, later in the day, the X5 won't crank or start anymore. At some point, the X5 complained about the battery being low in charge, so we charged. After charging to 100%, I retried, but same thing happened. The coil icon keeps on showing up on the dashboard when first turning on the X5. I put the fob in the key hole for 2 minutes, and restarted, but the X5 still won't crank or start.

Aside from the coil icon showing up when I first turn on the ignition, the X5 shows everything to be in OK condition.

OBD2 shows some errors, including P2457 and P2458 in history but not in PENDING/CURRENT. These errors were there before, so I don't think they're the culprit or related to the issue on hand. I did a DEEP OBD scan, and here's what I got:

CAS:
Treiber_KL50L_KS, Fehler momentan nicht vorhanden, aber bereits gespeichert
167200 km, 167200 km

CAS:
Treiber_KL50RS_KS, Fehler momentan nicht vorhanden, aber bereits gespeichert
167200 km, 167200 km

DME/DDE:
4A6E Glühstift Zylinder 1, Ansteuerung, Fehler momentan vorhanden und bereits gespeichert
167200 km

DME/DDE:
4A5E Glühstift Zylinder 2, Ansteuerung, Fehler momentan vorhanden und bereits gespeichert
167200 km

DME/DDE:
4A4E Glühstift Zylinder 3, Ansteuerung, Fehler momentan vorhanden und bereits gespeichert
167200 km

DME/DDE:
4A3E Glühstift Zylinder 4, Ansteuerung, Fehler momentan vorhanden und bereits gespeichert
167200 km

DME/DDE:
4A2E Glühstift Zylinder 5, Ansteuerung, Fehler momentan vorhanden und bereits gespeichert
167200 km

DME/DDE:
4A1E Glühstift Zylinder 6, Ansteuerung, Fehler momentan vorhanden und bereits gespeichert
167200 km

PGS:
Stossfaengerantennen_defekt, Fehler momentan vorhanden und bereits gespeichert
167200 km

I hooked up a booster pack to the X5, but attempting to turn the vehicle on still doesn't crank or start the X5.

I don't have warranty, and I'm afraid to bring this to the dealership without first understanding better the issue.

Please help. Thanks!

Could you please PM me? I need help with a similar issue. Thanks in advance!