3 DTCs and Red Battery Warning Light

[AeroLou]

Hi All,

I have a 2003 Z4 3.0i, with 103k miles on the clock.

Just drove back from Tesco and had a red battery light pop up! :x Scanned using a cheap little chinese ELM327 OBD Scanner and I had three DTCs come up:

- FF00 - No description given
- 281C - "DME: Bit-serial data interface (BSD): signal"
- 27DA - "DME: BSD generator"

Does anyone have any ideas as to what this combination of DTCs and battery light could mean? I would guess I am looking at a new alternator, or at least part of, but this isn't a small amount of money so want to be more sure before I get my wallet out!

For a little more background, I had another issue with the chassis electrical system before (that was due to a loose battery connector!), but tested both battery and alternator and they were outputting nominal voltage at idle.

Cheers for the help in advance

Edit: Referring to previously when I measured the battery, it was around 13.8V when idling over the battery which I have since found out might be outside of spec?

It has got worse this morning with power steering, ABS, TCS, Battery lights on and intermittent loss of interior electrical. I believe this might be due to the alternator not charging the battery?

Edit 2: It cranked very slowly but didn't start now. I will order a new regulator and alternator - if it isn't the regulator, I will put the new alternator in it!

 

[Joez4]

Sounds like the regulator has failed, when car is running it should be outputting between 13.5 to 14 volts.

The codes you have mean the dme can't communicate with the alternator, a new voltage regulator usually fixes this, if not then try cleaning the connector that clips into the back of the regulator with contact cleaner, that solved my issue after having no output from the alternator.

Don't skimp on the regulator, make sure its genuine bosch, my car came with a cheap unbranded regulator that would throw those codes.

In the end tho I had to replace the alternator to finally solve my issues