cdkbsd bsd fault bsd generator signal code 00281d

R

road warrior

Senior member
 Burton On trent
got a fault code.. cdkbsd bsd fault bsd generator signal
code 00281d

thoughts gentlemen ?? whatever has gone wrong it flattened the battery in mins, i moved the car this morning without a problem, went back to it an hour later to and click click click click ..... diag says
cdkbsd bsd fault bsd generator signal
code 00281d

i charged it up and the drain has disappeared, but the fault remains

thoughts ?
 
My guess this has to do with the alternator.
BSD stands for Bit Serial Data, which is the data protocol bus between alternator and ECU.

My guess is either the alternator or the rectifier on the alternator is at fault.

Or you have a broken bsd wire (or a defective ecu). But if its not the alternator, diagnosing BSD errors is very difficult as it is a proprietary standard (NXP) and not a general obd or can standard.
 
thank you, so if i replaced the alternator ? can you fix a rectifier ? the alternator IS charging i know, who could find/change the bsd wire ?
my obvious worry is driviing to get it fixed/diagnosed and breaking down on the way
 
double check battery terminal is tight as we did unplug it when doing the airbag module, it might be just your alternator is giving up and needs replacing.
 
I think it is something to do with communication between ECU and alternator, never had it but did a search. Not seen anyone whos fixed it yet so when you do ................ please share :D
 
oh where did those days go when you knew it was an alternator cus thr battery was flat or a light came on ..

suddenly hankers for a dynamo and voltage regulator that you tuned with a screwdriver :rofl:
 
road warrior said:
thank you, so if i replaced the alternator ? can you fix a rectifier ? the alternator IS charging i know, who could find/change the bsd wire ?
my obvious worry is driviing to get it fixed/diagnosed and breaking down on the way
Click to expand...

The bsd wire is the connector that goes into the alternator (so not the big red wire but the smaller black connector).
You can check if thats still connected or damaged.
Have you measured the battery voltage with the car running? How much was that?
I think you can get the rectifier/voltage regulator as a separate unit (it bolts from the alternator).
From bmw its (obviously) pretty expensive (about 120 quid), but in the aftermarket for about 30 quid.

BMW partnumber for the voltage regulator is 12317515319
Bosch partnumber is F 00M A45 219

If you're not comfortable with dismanteling an alternator (the rectifier is at the back, you dont have to open the complete alternator) you have to buy a new one. (an original bosch is in the aftermarket about 220quid, the bmw price... I'm not gonna list :rofl: )

Whatever you do with your alternator: always detach the battery first!
 
thank you !
i think i saw about 14 volts when it was working before and after it went silly this morning , as i say.. its not draining like a mad thing now, this afternoon i have charged it up ( its a new battery) and left it disconnected and will look tomorrow morning and see what it does, a strange clue is the car says its +40c outside, dead short/open circuit maybe ?
those part no' s for a 2005 3.0 ?
the previous owner said he had a flat battery and when he replaced it it had christmas tree lights up.. its seems likely whatever this problem is, killed his previous battery too
 
" Whatever you do with your alternator: always detach the battery first!"

hey. im only HALF as stupid as i look ! :rofl: erm..
 
14 volt is quite high I think? (should be around 13,5V I think).
Measure it in the morning with the engine running. 14 V could mean the voltage regulator is indeed bust. Be sure to change it quickly, otherwise you can also change your battery.

Those numbers are for the pre facelift 3.0 voltage regulator.
 
more clues are coming in .. thank you chaps . i will report back in the morning with the charging voltage ! change it.. is this the thing that bolted to the alternator ? anybody got one lying around for a 2005 3.0 ? i know i never cease to be amazed at you lot.. :D

and the strange indicated 40c outside temp ? its connected to the ecu somehow cus i know of one fella who had a reading of minus something and his roof refused to open - talk about nanny state :)
might it be -40 indicating a busted faulty connection ? is the external temp sensor in the nearside wheel arch - and where does the lead connect to ?
 
Assuming the same as an E46 -40 means it is disconnected/open circuit.



Or bloody cold :D
 
guess what, found the sensor, its been dragging along on the ground..duh.. ohhhh ebay i will go , ebay i will go eeeiadeo ebay i wlll go..
tha nice leccy man said......alternator to blame, but working ok atm. he thinks... its been sitting around since feb, and might be a bit of surface rust somewhere, and think if i run it it might fix itself - so before i lay out some moolah, try it for a while ... oooooooooo a shopping i will go .. the fastest shopping trolley ever seen at asda's.
It charging at 14.03 and drops when you load it.
 
Did u ever fix this issue. I'm getting a no start with no bsd signal to DME fault. Any help would be appreciated. Thanks in advance.
 
Faulty regulator that is in the back of the alternator going bad is the cause of that code so its not communicating with the DME, when that happens the alternator gets pegged at 14v charge rate as the DME can't control the charge rate. Just been through that, supplied with the wrong alternator and that couldn't communicate got the same code 281D. Put a used alternator on and that can communicate and regulate the charge rate as required. Its also interesting to know that the oil level sensor in the sump is also connected in the loom on the same circuit, if that goes bad it can bring down the signal from the alternator and vice-versus. As stated earlier the regulator can be changed by taking the rear cover off the alternator and putting a replacement in using the oem part number you should find a new regulator on ebay for decent money as opposed to replacing the whole alternator. My car has 94k miles on it and it was the original alternator so I went for a new alternator as the old one was not producing a charge.
 
colb said:
Faulty regulator that is in the back of the alternator going bad is the cause of that code so its not communicating with the DME, when that happens the alternator gets pegged at 14v charge rate as the DME can't control the charge rate. Just been through that, supplied with the wrong alternator and that couldn't communicate got the same code 281D. Put a used alternator on and that can communicate and regulate the charge rate as required. Its also interesting to know that the oil level sensor in the sump is also connected in the loom on the same circuit, if that goes bad it can bring down the signal from the alternator and vice-versus. As stated earlier the regulator can be changed by taking the rear cover off the alternator and putting a replacement in using the oem part number you should find a new regulator on ebay for decent money as opposed to replacing the whole alternator. My car has 94k miles on it and it was the original alternator so I went for a new alternator as the old one was not producing a charge.
Click to expand...
I did exactly this and it cured my issue. Just looked and the ebay dealer I got mine from is no longer selling them, but there must be others on there.
You can do the job in situ too, so fairly straightforward.
 
colb said:
Faulty regulator that is in the back of the alternator going bad is the cause of that code so its not communicating with the DME, when that happens the alternator gets pegged at 14v charge rate as the DME can't control the charge rate. Just been through that, supplied with the wrong alternator and that couldn't communicate got the same code 281D. Put a used alternator on and that can communicate and regulate the charge rate as required. Its also interesting to know that the oil level sensor in the sump is also connected in the loom on the same circuit, if that goes bad it can bring down the signal from the alternator and vice-versus. As stated earlier the regulator can be changed by taking the rear cover off the alternator and putting a replacement in using the oem part number you should find a new regulator on ebay for decent money as opposed to replacing the whole alternator. My car has 94k miles on it and it was the original alternator so I went for a new alternator as the old one was not producing a charge.
Click to expand...
I have codes 281D and code 0027C3 which is Oil level sensor like you have mentioned should I change both alternator voltage regulator and the oil level sensor or just one of them??
 
TcS Trippin said:
I have codes 281D and code 0027C3 which is Oil level sensor like you have mentioned should I change both alternator voltage regulator and the oil level sensor or just one of them??
Click to expand...
What engine? If it's M54 you have a dipstick so the oil level sensor isn't so important.
If N46 or N52 then change the level sensor in line with an oil change as it is in the bottom of the sump.
 
enuff_zed said:
What engine? If it's M54 you have a dipstick so the oil level sensor isn't so important.
If N46 or N52 then change the level sensor in line with an oil change as it is in the bottom of the sump.
Click to expand...
thank you, yeah I have the M54B25 also have just done a oil filter change 2 days ago so not so keen on replacing it aha
 
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