I drove home in my '08 R56 Mini Cooper (no S) 2 days ago and parked, everything was fine.
The next morning I try to start it but it will not crank or start. When inserting the key the dash illuminates, the lights turn on, everything appears normal. When pressing the starter button I hear an "electrical hum" noise and then nothing. No clicking noise, no engine turn.

Here is what I tried so far:

• I figured it may be the battery so I took it out and charged it for a few hours. Put it back in later, exactly the same situation.
• I checked the clutch pedal switch but it seems fine. I disconnected and reconnected the little plastic slider on the side that holds the wire connector.

I appreciate any help! Thank you!

Here is a video of what is happening:

 

When you touch the Start button, it seems like the clutch pedal switch is not working: You can see how the gas tank status is "filled" just like when you touch the Start button without pressing the clutch.
Are you pressing it in the first attempt?

Later it seems it is the battery or the starter.
I would try changing the battery with another one (just for testing, for example with the red Mini in front of you) and not just charging the current one.

Let us know

 

Yep, I would suspect the battery as well. Let me guess, is the original battery?

 

Old threat I know, but wondering if you ever figured this out. Having similar situation. Thanks

 

This recent thread may help you troubleshoot the issue.

 

thank you- I will take a look at that!

 

If you have a scan tool, you may be able to verify that the CAS control unit is supplying battery voltage and/or sufficient amperage on terminal 50L to the starter solenoid when you try to crank the engine with the start/stop button. Also check for fault codes.

 

Ok, I used bimmerlink and found code A0B4- what are the next steps for further diagnosis? Thanks for help!

 

Connections at battery seem secure, ground wire also seems secure. So it could be starter, solenoid, or CAS? Starter is really buried. Is there a fuse or relay to check first?

 

Do you have a scan tool that reads live data from the CAS module?
Do you have a multimeter?
How old is the battery?
Do you hear any noises when you try to crank the engine?
A0B4 simply means that the CAS module is trying to crank the engine but detects no engine turning (rpm).

 

I don’t believe bimmerlink app can read live data from cas, just regular data when engine is running
do have a multi tool-
I replaced and registered a new battery a few weeks ago, was overdo and the old one may have strained the starter?
new battery reads 12:5
trying to hear a click or priming sound but the up down headlight noise is dominating. Will try again when someone else is around to push the button

 

Hearing the starter solenoid click when the start/stop button is pressed would suggest that the solenoid receives adequate terminal 50 voltage from the CAS module to close the starter motor circuit.

If you can show that the solenoid gets voltage from the CAS and clicks, then you would perform separate voltage drop tests under load on the power and ground sides of the starter motor circuit to look for possible extra resistance that prevents the starter motor from turning. If there is no extra resistance, then the starter is bad and requires replacement.

 

Okay, good to know. I may need to have someone else do that as I don’t have a workspace right now, but good to have a direction. The car is due for a timing chain, and reading further online I’m now nervous to try starting it before confirming the starter is at fault. It didn’t make any significant noise when I turned it off last night, and there was no crank at all this morning, so hopefull6 just paranoid. I also don’t know if the a0b4 code would suggest or rule that out. Thanks again for time a feedback!

 

Are you saying that the starter was cranking the engine yesterday?

I believe that A0B4 simply confirms what you already know: The starter isn't turning the engine.

A0B4 seems to say that the CAS module received a signal to supply voltage to terminal 50 but did not receive an engine rpm signal confirming that the engine actually cranked. Whether battery voltage actually reached terminal 50 or the starter solenoid would require a good scan tool that reads live data from the CAS module or a multimeter voltage reading at the starter solenoid connector (or evidence that the starter solenoid clicks).

 

Yes, has been cranking fine with the new battery. Got it, that makes sense.