[Dev01]

Hey if anyone can help me out before I end up taking it to a shop than I would appreciate it a lot.

2007 BMW 335i

I was driving home, halfway through the drive I heard a loud bang and then boom, power steering gone and my dash lit up. Managed to get the car back home and the next morning I checked the hood and found that my serpentine belt had snapped and there was a ton of oil everywhere.

Figured it was OFHG & OCG that caused the belt to snap so I went and replaced both and threw in a new serpentine belt kit.

After I changed the OFHG I went to bleed the coolant and found out the coolant pump wasn't bleeding. (Car on, engine off, hold gas for 12-15secs, max heat and lowest fan speed)

Pulled up Ista and read the history since I had not checked the codes at all yet and I found a bunch of DME and BSD codes.

- 5E1A: Engine Management: Interface
- 3100 DME: Boost-Pressure control, deactivation
- 2E97 DME: Alternator
- 2E8B BSD, message; Intelligent battery sensor: missing
- 2E84 BSD, message, electric coolant pump missing
- 2E7C BSD data bus communications fault
- 2DED DME Power management, closed circuit violation
- 2DEB DME Power management, vehicle electrical system
- 2A95 DME: Crankshaft sensor, synchronization
- 29f5 DME: Catalytic-convertor conversion 2
- 29f4 DME: Catalytic-convertor conversion
- 2A17 DME: DMTL, system fault
- 2E82 DME Electric Coolant pump, cutoff

I went and checked the fuses:
1 in black box under hood - good
1 under the hood near the passenger side - good
1 in the trunk above the battery - good

I also measured the voltage on the connector and i got 12v

I then thought maybe the Water Pump had gone out, I bought this car recently and the previous owner had said the water pump was replaced, but knowing how bad these pumps are I went and installed a new one. Deleted the old codes and ran a test on ista before plugging in the pump no codes, plugged in the pump and tried bleeding it and now with the new pump installed I have the code: 2E84.

At this point, I'm kinda just curious and decide to start up the engine to see if the car will crank and the car starts up just fine with no issues. But continues to throw the water pump error and the water pump visibly doesn't look like it's running.

[StradaRedlands]

Looks like a partial BSD bus problem. You ruled out the water pump, so it's somewhere else on the bus. Either one of the components, or actual wiring/plugs of the bus. DME codes are may be related, or something different...

[Dev01]

Originally Posted by StradaRedlands

Looks like a partial BSD bus problem. You ruled out the water pump, so it's somewhere else on the bus. Either one of the components, or actual wiring/plugs of the bus. DME codes are may be related, or something different...

from my understanding even if it is a BSD issue, shouldn't the water pump go into its failsafe mode and run on 100% if its receiving power? Even when I started the engine up the pump made 0 noise.

[StradaRedlands]

Not if it isn't getting any current. Bad wiring would wipe it out entirely.

[Eoin92]

My engine fan was not working at all now it's running a lot at full speed. Would this also indicate a bus problem?

Do we have any bus debugging guides? I have been trying to understand the pt / k can differences and also the changes made from previous to 2007+

Can't find much on it, I have a USB canbus debugger and an oscilloscope. So if there is something technical to follow I'd love to see it. (I'm new to canbus but should be able to follow if there is a guide and would be happy to rewrite for a beginner if there is any content existing)

[oVeRdOsE.]

alternator code?

The serpentine flew away and it took out the waterpump ground with it ? (ground is very close to the crank pulley)

[Dev01]

Well, I ended up taking it to the shop and it turns out that the battery got way too low after the serpentine belt snapped. The new battery fixed all the issues and the car is on the road again!