[relative4]

'07 335xi auto, 145K miles. I drove it this morning, and it was perfect. Then my wife took it to work as usual. As she was almost getting home, it lit up pretty much every light on the dashboard and started shutting down. She limped it home, and the first thing I found was a bunch of coolant around the reservoir. Ordinarily I would assume that the reservoir had cracked, but (a) the leakage all seems to be from the cap, and (b) the codes below say something else is at the root of this.
Going over the list of codes, my first guess is that a bad voltage regulator or alternator shut down the water pump, causing the overheating that caused the reservoir cap to release coolant pressure.

What do you guys think?

A couple of notes:
The 2E8E is there because the IBS has been disconnected for 6 years. Caused too many problems.
The 9CCD is probably accurate; the driver side mirror has been a little flaky lately.

DME/DDE [MSD80] | 2E8E: BSD, message; intelligent battery sensor (IBS): Missing
DME/DDE [MSD80] | CDA1: Message (steering wheel angle, 0xC4) incorrect, receiver DME, transmitter DSC
DME/DDE [MSD80] | CD95: Message (operation, cruise control/ACC, 0x194) incorrect, receiver DME, transmitter DSC / SZL / LWS / ACC
DME/DDE [MSD80] | 2E82: Electric coolant pump, cutoff
DME/DDE [MSD80] | 2E98: BSD, message; alternator: Missing

JBBF [JBBF87] | A6CF: AUC sensor
JBBF [JBBF87] | C910: No message, receiver JBE, transmitter IHKA

EKP [EKPM60_3] | No errors found

FRM [FRM_70] | 9CCD: Drive, mirror, driver's side, faulty
FRM [FRM_70] | A8B6: Brake light, left, faulty

KOMBI [KOMB87] | 931D: Undervoltage or overvoltage
KOMBI [KOMB87] | E104: No description found

VGSG [VGSG90] | 53FC: Supply, control module: terminal 30
VGSG [VGSG90] | 53FD: Supply: terminal 30g
VGSG [VGSG90] | 55C3: AWD limp-home control activated. No DSC specified nominal torque.

RDC [RDC_CAN] | 604D: RDC control module
RDC [RDC_CAN] | 604E: RDC system
RDC [RDC_CAN] | 6057: Wheel electronics, rear right

CAS [CAS] | A0B5: Fault, road speed signal

KLIMA [IHKA87] | 9C6C: Supply, switch center, center console 12 V

FAS [FAS_PLX] | No errors found

MOSTGW [RAD2_GW] | E18D: No description found
MOSTGW [RAD2_GW] | E190: No description found

DSC [DXC_90] | D36D: No F-CAN message (SZL, 194)
DSC [DXC_90] | 5ED2: Interface, rain/light sensor
DSC [DXC_90] | 5EBA: Steering-angle sensor, plausibility
DSC [DXC_90] | 5F3A: Transfer case: internal
DSC [DXC_90] | 5DD0: Control module, overvoltage
DSC [DXC_90] | D359: F-CAN No message (SZL, C9)

MRS [MRS5] | 93D1: Over-voltage
MRS [MRS5] | 940A: Overvoltage during self-test

TEL/MULF [TELE60_3] | No errors found

RADIO [SAT_60] | No errors found

AMP [AMP_60] | No errors found

EGS [GS19D] | 5014: Power supply
EGS [GS19D] | 51B0: signal from DSC implausible: brake-light switch

MASK/CCC [RAD2] | No errors found

FZD [FZD_87] | No errors found

[Serf27]

DME 2E98 is where you should start. Most likely the regulator.

[relative4]

Originally Posted by Serf27

DME 2E98 is where you should start. Most likely the regulator.

Yes indeedy. Pulled the regulator, and the brushes are worn out.

Before doing that, I went ahead and had the battery checked. To my astonishment, the 7-year-old Interstate is still going strong.

[Daaaaaaaan]

Brushes will have a lot of wear over that mileage + age, but unlikely for worn brushes to cause the Christmas tree on the dash. My thought would be contamination (either coolant directly or washed in by it) that can be cleaned off.

Had a similar experience (but with oil… don’t ask): Christmas tree, gauge needles going to zero but a few seconds later everything back, but two different episodes. Then inconsistent alternator charging.



Sprayed a can of CRC lectra-motive on the alternator and that resvolved it. still going strong for last 3 years. Still on oem alternator and regulator: similar to your age and mileage.

[relative4]

Got the new VR in, and the only code now is a 2E97; description in ProTool is alternator overheating. The code came up within a few minutes of starting the car, and it comes back consistently after clearing. Any other things I should check before replacing the alternator? Any chance this is a temporary condition while the alternator plays catchup with a low battery?

[relative4]

The thread below seems to indicate that the 2E97 is common with new VRs. Is anyone familiar with this issue or the resolution? FWIW, the code does not cause any lights, and the thing runs and charges fine.

https://www.e90post.com/forums/showp...7&postcount=15

[BRG_N54]

Originally Posted by relative4

Got the new VR in, and the only code now is a 2E97; description in ProTool is alternator overheating. The code came up within a few minutes of starting the car, and it comes back consistently after clearing. Any other things I should check before replacing the alternator? Any chance this is a temporary condition while the alternator plays catchup with a low battery?

Was the new regulator genuine Bosch? If not I would tack it up to that. If it was then you could also check the clutch operation of the pully. Need to remove the belt and verify the pully only spins one direction, it should freewheel in the opposite. If that checks out might be time for a new alternator....you guessed it, a Bosch one only!

[relative4]

Follow up on this: after 3 weeks, the battery that had just tested good died. Pretty badly - it swelled up and stuff. Looked like a pretty solid overcharging situation. I installed a new alternator, and installed and registered a new battery. 2E97 gone, and working flawlessly for the month since. I even connected the IBS, and the defroster, which used to not work with the IBS connected, works.
So much for the cheap fix.