technical F30 320d Start Issue

[KashR]

Hi everyone,

I've got a strange issue on my F30 320d.
The car does not want to start in the morning, it throws up a lot of random errors on the dash, drivetrain fault, fuel supply and flat tyre monitor.
After I press the start button about 5-6 times the car starts perfectly normally.
The car will then start like normal for the rest of the day and only the next morning will it have this issue again.
I've got a new battery in it, about 3 months old now and had it tested just to be sure it wasn't the cause, battery checked out fine.

Anyone have an idea of what the cause may be?

 

[momo1]

did you get an AGM battery?

 

[KashR]

Yes I've got an AGM battery and registered it as well

 

[MR_Y]

Hi
Is there a tracking device fitted and has it been checked recently? It could be draining the battery overnight. Also, if it has more than one tracker fitted (sometimes the first owner's device is never removed) that could drain the battery too.
Just speculating...

 

[KashR]

So just some feedback on this, the issue is not resolved yet.
The vehicle does not have a tracker so that can't be draining the battery.
Workshop has checked the starter, alternator, wiring etc but can't find the problem.
The car does not throw any fault codes at all that relate to the starting issue.
Any idea what else could be causing this?

 

[KashR]

I would like to book the car into a BMW specialist workshop, maybe they would find something that the others have missed. Any reputable shops in the Randbug area? Tunetech seemed to come highly recommended however they're about 40 minutes away from me

 

[sash]

do you have a obd tool to check the voltage when starting, alternatively try to get into the hidden menu and voltage when starting. It could be related to the alternator. If the alternator is under charging, the car might struggle after being parked overnight, but starting after a short while will be fine. Most of the electronics are susceptible to low voltage which could explain the errors.

When doing the battery test , did they test the charge rate? Did they also do multiple starts? I had an experience once where a new battery would struggle to start after being parked for maybe day or 2. It passed the battery test and alternator was fine, but after about 3-4 consecutive starts the voltage began to drop enough that the car struggled to start. Battery was replaced in this case.

 

[KashR]

So I've finally got this issue resolved. After getting cr@p advice from another BMW specialist who insisted that I have to have an agents battery in the car (bought and installed, didn't solve the issue).
I took the car to Tune-tech, they identified an issue on the ECU a bad earth connection. Repaired it and the car has been perfect ever since