Will not start condition ‘08 4.8 with error codes
 

Ok, so my 2008 X5 4.8 won’t start. Not a battery issue, that’s been disconnected and charged fully to make sure (although I’m at 11.86 volts, which seems a bit low, but the starter isn’t making any attempt but i will test the battery in case).

I’m getting power to everything but when the start button is hit, I hear the relay trying to activate the starter, but the starter doesnt go. It also seems the brake petal is very firm.

I have 3 codes thrown (in addition to some random dash lights):

D904 Kcan wire fault
A0B4 Engine start, starter operation
A0B2 Supply, terminal 30E

Anyone have success differentiating between a bad starter and a bad connection at the battery with the safety terminals? Does the A0B2 code imply it’s the safety terminal connection?

Insight would be appreciated. Thanks!

11.86 is low. A fully charged battery will be in the 12.5v range

Toss in a bad IBS....

(And I'm not talking irritable bowel syndrome ...)

Where are you measuring 11.86? Battery terminals?

Yes.

The issue though, I’m getting no action or attempt for the starter to activate. No cranking sound, no attempt to crank, nothing. I recognize 11.86 is low, but shouldn’t be low enough to cut off the starter motor completely.

Jumping it was obviously attempted as well, and it does nothing. The same condition exists, nothing from the starter, no attempt to move. So, I don’t think it’s explained by the battery.

Technically 11.86V is a dead battery. I doubt you even have the amperage needed to activate the starter solenoid.

Again, with a starter box attached, same symptoms. So it’s not the voltage to the starter.

Just to put that to rest, I attached a different battery, same symptom. No motion from the starter. I understand that these cars are very sensative to battery voltage, I’ve gone through a regulator and changed batteries on it before. This isn’t a battery problem.

So, does anyone have anything other than the battery?

I’m thinking it’s the starter (which reads to be a common fault), but before I go through the rather involved process of changing it, I’m just trying to make sure I’m not missing something else like the blow out safety terminal connection (which I’ve already checked at this point, they seem good).

Thumbs up!!

Most jumper boxes cant even begin to jump a bimmer. So if your using a jumper box forget it.
Call AAA and get a proper jump.

Then you'll know.

Sent from my SAMSUNG-SM-N920A using Tapatalk

Well, if you are getting voltage AT the starter- like 12+ volt when using another battery- and the starter isnt moving, that would be an indicator.

We have seen a few dead starters...not entirely out of reason

Starter's aren't high failure parts on these trucks. If battery SOC is below ~30%, DME won't even attempt to engage starter.