Car no start. Electrical issue. Help is much appreciated.

Rezh95 · 01-12-2016, 03:55 PM

2009 335i M Sport
The car will not start. It just makes a click noise when trying to turn it on.
The car has given me 3 codes.
Immobilizer System:
CAS
Driver KL50L KS
Code: A0C1

engine starter faulty operation
Code: A0B4

Motor Control:
Engine / Motor
Generator, communication: Bus error
Code: 2E98

The BST has been replaced. New starter. New battery. New key fob. Battery registered with my Carly app. Fuses and the 2 relays in the glove box have been checked. As far as I know, grounds have been checked (unless I didn't locate all of them) the only time the car starts is when it's being boosted by the front engine bay terminals, and car will eventually die after a few minutes. When I tested the batteries voltage as it was idling. The voltage decreased to 11 volts instead of increasing to 13-14. I've done so much looking and research yet I haven't found anything. Any ideas please?

patents · 01-13-2016, 02:49 PM

Hey, you're in Memphis too.

If I was to guess there's a bad connection somewhere, it may not be ground, it may be a positive connection. Check all connection nuts on the positive cable and leads under the hood, and the starter connection. Search around for info on the A0C1 code and try out what people are suggesting.

If the alternator was bad (simply not putting out charging voltage), I would think the car would at least start with a charged battery. But a bad voltage regulator can cause all sorts of odd things. The 2E98 code may suggest a bad alternator (car can't communicate with it), but this may all go back to a bad connection somewhere.

I bet you have a bad positive connection somewhere.

01-12-2016, 03:55 PM	#1
Rezh95 New Member 0 Rep 6 Posts Drives: 2009 BMW 335i LCI M Sport Join Date: Jan 2016 Location: Memphis, TN iTrader: (0)	Car no start. Electrical issue. Help is much appreciated. 2009 335i M Sport The car will not start. It just makes a click noise when trying to turn it on. The car has given me 3 codes. Immobilizer System: CAS Driver KL50L KS Code: A0C1 engine starter faulty operation Code: A0B4 Motor Control: Engine / Motor Generator, communication: Bus error Code: 2E98 The BST has been replaced. New starter. New battery. New key fob. Battery registered with my Carly app. Fuses and the 2 relays in the glove box have been checked. As far as I know, grounds have been checked (unless I didn't locate all of them) the only time the car starts is when it's being boosted by the front engine bay terminals, and car will eventually die after a few minutes. When I tested the batteries voltage as it was idling. The voltage decreased to 11 volts instead of increasing to 13-14. I've done so much looking and research yet I haven't found anything. Any ideas please?
	Appreciate 0 Tweet Quote

01-13-2016, 02:49 PM	#2
patents Lieutenant 164 Rep 598 Posts Drives: 2008 328i Join Date: Aug 2014 Location: Memphis, TN iTrader: (0)	Hey, you're in Memphis too. If I was to guess there's a bad connection somewhere, it may not be ground, it may be a positive connection. Check all connection nuts on the positive cable and leads under the hood, and the starter connection. Search around for info on the A0C1 code and try out what people are suggesting. If the alternator was bad (simply not putting out charging voltage), I would think the car would at least start with a charged battery. But a bad voltage regulator can cause all sorts of odd things. The 2E98 code may suggest a bad alternator (car can't communicate with it), but this may all go back to a bad connection somewhere. I bet you have a bad positive connection somewhere.
	Appreciate 0 Quote