Battery and starting problem in the M

no fit state

Senior member
UK
First problem of ownership :headbang:

My Bluetooth failed Saturday afternoon and didn't think to much of it other than damn I've got to source a new ulf unit for it. I then park the car up and don't drive it for the rest of the weekend.

So this morning (Monday) I go to get in the car to drive to work and the battery is completely dead. I open up the boot, take off the carpet battery cover and have a look at the battery. The little window that normal glows green is completely black. The battery is a aftermarket replacement that is just over three years old. So I nip up to ecp and pick myself up a new battery, get it fitted and the car starts fine. So off I go to work. on the way of my short journey I stop off at garage to use the cash point, but when I get back to the car and go to start it, the car cranks but just won't fire. I give it another go and after about 6 cranks the engine springs into action.

Once at work I check for a drain on the battery and all looks good. No more than 0.02 amps.

Anyway it comes to the end of the day I jump in the car and it fires up straight away and I head home. I park the car up and head indoors for no more than 10minutes before I'm back out to the car and try to start it. The bloody thing is cranking but not firing! So I give it a couple more goes and fires into action and I head down to my indie to explain the problem. Of course it wouldn't do it again while was with him! The car fired up after just a couple of turns.

Anyway he's going to read the codes tomorrow but I wondered if anyone hear had any ideas.

Cheers.
 
Z4M-2006 said:
Cam sensor possibly...

Maybe a dodgy fuel pump....

I was thinking fuel pump too, though once going the engine is running sweet. crank sensor would be a nice easy fix and hopefully not to expensive.

I forgot to mention the Bluetooth is working now, I'm wondering if the ulf is on its way out and drained the battery and that it turn has killed something else?
 
ULF staying live is very common throughout the BMW range...

Disconnect and see how you go ..
 
I'll definitely disconnect the ulf if I get another flat battery, but so far no drain on the battery from it, so for now it can stay connected.

Just a shame this starting problem has come from the back of it (or an unlikely coincidence?) anyway I guess I'll have to see what codes get pulled tomorrow.
 
I would say coincidence more than a battery change has caused the problem..
But ULF could be intermittently staying live and caused your initial problem ..
 
So I had the car scanned today and it's thrown the code 2f44 which points to the ews unit (immobiliser) Anyway the garage couldn't repeat the starting problem fault and it didn't happen when I started the car this morning and when I picked it up in the afternoon. So I'm going to monitor the situation for a couple of weeks before replacing it.

No fault codes for the ulf unit which touch wood is also working as should :-)
 
Hmmm...

EWS wouldnt drain your battery,perhaps it just dropped a cell and went kapput..

The ULF wouldnt show any faults,there isnt a fault peg for it staying on or not falling to sleep...

The 2F44 can come up when the car is cranked with low battery power.... The DME/EWS manipulation protection can kick in...
I dare say now the car has recognised its codes and realigned the EWS...
 
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