BimmerFest BMW Forum banner
1 - 20 of 30 Posts

·
Registered
Joined
·
58 Posts
Discussion Starter · #1 ·
About 7 months ago the 2006 e60 530i caused me MOST grief until I deduced it was due to a negative batt terminal assembly preventing the MOST devices from waking up. So it wouldn't start. Replaced neg batt term; problem solved, life went on.

The current problem is on my 2008 e60 528i, 220K mi. It presented while my daughter was driving along, by displaying the christmas tree of error lights on the instr cluster. Scared her enough to call me,; she ended up abandoning it in a parking lot. Dad rescued the car later. While driving it home, I noticed the MOST bus triying to reset, the assorted devices working for a second or so then turning off, repeating over and over. Body control module, CCC, IHKA, radio, etc. I limped home but, the vehicle is pretty much un-usable at this point.

Read codes with ISTA; seemed like the Sat Radio module was malfunctioning so I bypassed it's MOST fiber optic port with a loop. BTW, the error count was in the 30s; I didn't freak because I figured it is mostly MOST loop related. Plenty of devices on this car are on both the MOST ring and the other buses in the vehicle. If you break one comm link, it may cause problems with another bus.

Now, when I clear all the codes, I'm left with 6 or so which still don't bother me too much (pic trail to follow this initial post). What bothers me is once I clear the plethora of MOST/other bus related error and start the car I get back to the 20-30 error avalanche. And worthy of note is that while starting the ISTA Vehicle Test,I get a "Resetting MOST in x seconds"countdown; only after ISTA resets the MOST ring will the error codes (Vehicle Test) download complete. Seems like the MOST ring will not stay functioning.

I checked for red light at all the likely MOST ports; Sat module, TCU and at the MOST interface in the glove compartment. I get blinking lights wherever I check.

Pictures of process follow...
 

·
Registered
Joined
·
58 Posts
Discussion Starter · #9 · (Edited)
So, it's late; I just wanted to get this out there in case anyone had run into anything remotely resembling my situation. I hope I posted this right; this is my first time using the new Bimmerfest interface. Just noticed the pics were focused really lousy. Oh well, I'll pay more attention when I take pics next.

Ty in advance for your attention!
 

·
Nuclear engineer
02/2012 X5 35d M57Y CPO 119K miles NOKIAN WR G3 30K miles
Joined
·
23,116 Posts
I read almost every well formed question here on BimmerFest - being retired and avoiding television, BF is next best. Your’s is the first that I have noticed with recurrent MOST problems and in two different platforms! I’ll watch here and maybe learn something. Best wishes
 

·
Registered
Joined
·
375 Posts
Typically a mass of seemingly unconnected errors like that, plus 'undervoltage' and 'IBS missing' errors staring at you, that all makes me think you have IBS or weak battery issues, certainly not uncommon on these cars.
My IBS showed the same 'missing' code at one point, but I also had recurrent issues with low voltage and increased discharge warnings, I'm guessing because the IBS wasn't shutting off all systems in the car (or something). Constant recharging of the battery only worked so well till I replaced the IBS and Adapter, part #s 12427603567 and 12517615476. I haven't had an issue since replacement, even with the car sitting for 3 weeks at one point, which in the past was a sure way to cause problems.
 

·
Registered
Joined
·
58 Posts
Discussion Starter · #14 ·
Typically a mass of seemingly unconnected errors like that, plus 'undervoltage' and 'IBS missing' errors staring at you, that all makes me think you have IBS or weak battery issues, certainly not uncommon on these cars.
My IBS showed the same 'missing' code at one point, but I also had recurrent issues with low voltage and increased discharge warnings, I'm guessing because the IBS wasn't shutting off all systems in the car (or something). Constant recharging of the battery only worked so well till I replaced the IBS and Adapter, part #s 12427603567 and 12517615476. I haven't had an issue since replacement, even with the car sitting for 3 weeks at one point, which in the past was a sure way to cause problems.
Ty for your reply MR. I disconnected the IBS to take it out of the loop; I've had problems before with bad IBS. Battery was the first thing I checked, 2.5 yrs old, 900Ahr, good quality, charged 100% and checked with my Centec internal resistance tester; tested ok. Hauled it to O'Reily, got them to use their load tester, checked ok too.

It's odd that I can have batt charged to 100%, with a 25A solid state charger on it and when I start the engine is when I get the flood of errors. I would think that rules out undervoltage (?).

There seems to be a battery drain; it was at 12.6V or so last night, woke up this morning at 11V. Not good; going to have to look into why the excessive batt drain protection isn't working right (disconnected IBS?). And what is draining it.

Starting to question alternator function, maybe I can use ISTA to test it. All this may be related to alternator.
 

·
Registered
Joined
·
58 Posts
Discussion Starter · #15 ·
IBS uses BSD and not MOST
Ty Doug, I am seeing BSD errors btw. Once from a missing water pump (not persistent), now from missing alternator (persistent). Alternator problems? I'll have to pull some plastic off and take a look around at least.
 

·
Registered
Joined
·
58 Posts
Discussion Starter · #16 · (Edited)
Hmmm, I may be on to something. Voltage at battery with engine running 1500rpm is ~17.8V. I've never seen alternator put out that much voltage.

My indy shop guy tells me he's never had luck with rebuilt alternators for BMWs. Anyone buy one lately, new? I can get a new Valeo from rockauto for $300.

Found out it's got the wrong alternator on it, 150A, should have 180A according to realoem. This car had a long (maybe sordid history) before it came to my garage. Unlike all my other BMWs, which I know most of their history.

I'm thinking I'm going to roll the dice on a new Bosch 180A unit off Amazon for $167.
 

·
Nuclear engineer
02/2012 X5 35d M57Y CPO 119K miles NOKIAN WR G3 30K miles
Joined
·
23,116 Posts
BSD alternator output is commanded by the ECU. Electrical system current is determined by Ohm’s Law V=IxR and voltage. The only system voltage sensor is the IBS.
 

·
Registered
Joined
·
58 Posts
Discussion Starter · #19 ·
I've got very nearly all the same codes in my 04 e60. Only two things I have left to change are the IBS and the alternator
Check your voltage at the battery with the engine running. if it's above 15.5 and you've got a battery registered as flooded acid or AGM, the voltage regulator at the alternator is suspect. I don't think it's worth changeing just the regulator, especially if you've got some miles on the alternator.

I've got a new complete alternator on the way, decided not to go with rebuilt.

Also, Google "BMW error code 00951B", which just recently came up on mine with no description on ISTA. Lots of history on alternators, voltage regulators.
 
1 - 20 of 30 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top