Voltage issues

zayza · 03-25-2025, 10:26 PM

A few days ago all of the warning lights had popped up on the instrument cluster, then went away after a few seconds. This repeatedly happened during the drive home.

Hooked up my scan tool to monitor and read codes. I notice my Voltage getting past >15v during idle, and up to 14.7v while driving.

Today I replaced the alternator with a Bosch one in hopes the alternator or voltage regulator had gone bad. This did not help, the voltage is the same. All my gauges stopped working and it threw a bunch of codes on the drive home.

Codes

DME
-00CD9F -00CDA0 -00CDA8 -00CDA9 -00CDAA -00CDAB -00CDA8 -00CDA9 -00CDAA -00CDAE -00CDB1

EGS
-00CF14 -00CF19 -00CF1A -00CF1D -0OCF1E

VTG
-0055C3

DSC
-005EFC -005F49 -00D35A -00D35C -00D35E

MRS
-0093FB

KOMBI (Instrument Cluster)
-00АЗАВ -00АЗАС -00АЗАЕ -00АЗВС -00A3BD -00A550

CAS
-00A0B0 -00A0B1 -00A0B4 -00A0B5 -00A118 -00D904

JBE
-00C907 -00C908 -00C914 -00C91E

TCB
-00E147 -00A9FA

SMFA (Driver seat module)
-00E444

FRM
-009CAC -009CC6 -00E584 -00E594 -00E597 -00E599

IHKA
-00E704 -00E707 -00E717 -00E71A -00E71B -00E71C -00E720 -00E729

Has anyone experienced anything like this? Any help with troubleshooting to resolve this problem would be greatly appreciated!

-2011 328ix with 100k miles. N51

RockCrusher · 03-26-2025, 07:51 AM

In some cases the voltage regulator is not at the alternator but is located elsewhere. I searched for a BMW F30 voltage regulator and got some hits and all pictured were *not* part of the alternator.

I watched a video of one voltage regulator replacement and the voltage regulator was located on the passenger side of the engine compartment and back in the corner of the engine compartment.

'course, google can't be a substitute for being at the car. Since you are at the car you will have to confirm the voltage regulator is part of the alternator. If not then the voltage regulator is suspect.

If the voltage regulator is part of the alternator then the battery -- and battery cabling/connections -- come in for suspicion.

The battery connections/cabling at the battery posts come in for suspicion sure but the cabling/connections at the other end of those cables -- and if fitted ground straps -- need to be checked. These seldom if every get eyeballed.

03-25-2025, 10:26 PM	#1
zayza Registered 0 Rep 3 Posts Drives: 2011 328xi Join Date: Mar 2025 Location: PNW iTrader: (0)	Voltage issues A few days ago all of the warning lights had popped up on the instrument cluster, then went away after a few seconds. This repeatedly happened during the drive home. Hooked up my scan tool to monitor and read codes. I notice my Voltage getting past >15v during idle, and up to 14.7v while driving. Today I replaced the alternator with a Bosch one in hopes the alternator or voltage regulator had gone bad. This did not help, the voltage is the same. All my gauges stopped working and it threw a bunch of codes on the drive home. Codes DME -00CD9F -00CDA0 -00CDA8 -00CDA9 -00CDAA -00CDAB -00CDA8 -00CDA9 -00CDAA -00CDAE -00CDB1 EGS -00CF14 -00CF19 -00CF1A -00CF1D -0OCF1E VTG -0055C3 DSC -005EFC -005F49 -00D35A -00D35C -00D35E MRS -0093FB KOMBI (Instrument Cluster) -00АЗАВ -00АЗАС -00АЗАЕ -00АЗВС -00A3BD -00A550 CAS -00A0B0 -00A0B1 -00A0B4 -00A0B5 -00A118 -00D904 JBE -00C907 -00C908 -00C914 -00C91E TCB -00E147 -00A9FA SMFA (Driver seat module) -00E444 FRM -009CAC -009CC6 -00E584 -00E594 -00E597 -00E599 IHKA -00E704 -00E707 -00E717 -00E71A -00E71B -00E71C -00E720 -00E729 Has anyone experienced anything like this? Any help with troubleshooting to resolve this problem would be greatly appreciated! -2011 328ix with 100k miles. N51
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03-26-2025, 07:51 AM	#2
RockCrusher Colonel 2176 Rep 2,001 Posts Drives: BMW 2024 M8 Competition Coupe Join Date: Jun 2022 Location: Benton County, AR iTrader: (0)	In some cases the voltage regulator is not at the alternator but is located elsewhere. I searched for a BMW F30 voltage regulator and got some hits and all pictured were not part of the alternator. I watched a video of one voltage regulator replacement and the voltage regulator was located on the passenger side of the engine compartment and back in the corner of the engine compartment. 'course, google can't be a substitute for being at the car. Since you are at the car you will have to confirm the voltage regulator is part of the alternator. If not then the voltage regulator is suspect. If the voltage regulator is part of the alternator then the battery -- and battery cabling/connections -- come in for suspicion. The battery connections/cabling at the battery posts come in for suspicion sure but the cabling/connections at the other end of those cables -- and if fitted ground straps -- need to be checked. These seldom if every get eyeballed.
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