Dynamic drive inactive / many faults / transmission failsafe -- alternator issues

I have been having the Dynamic Drive Inactive fault once my car warms up and if it's at idle, sitting still the faults occur (once warm) with bringing up the RPM's -- also, normally followed by many other faults / parking brake / transmission failsafe, etc. I replaced the battery with a DURLAST from Auto Zone -- and still doing the same -- (have not had the car programmed to know it has a new battery -- the dealer sure frowned upon a non OEM battery but I don't trust that they really even know) --- From reading many forums, I'm 98% convinced it's the alternator (probably the voltage regulator) because I can bring up in the hidden menu in the instrument cluster the operating voltage -- when I first start the car it runs around 11.8 volts (too low, right?) -- then at some point when the car begins to warm up, you can feel / hear a small drag on the motor and it bumps up into the 13's to low 14's --- However, when the faults begin to happen when driving - the Voltage is more volatile, and goes through 14's 15's and when in gets to the 16's it faults (with all the lights in the dash going out then blinking) --- Seems logical it's the alternator spiking causing the faults, etc. After an extensive search, I just got one today (air cooled Valeo 180amp)-- a place called Maniac Motors in Dallas rebuilds them for about $180 (net of $60 core charge) and had one in stock, they use genuine Valeo parts. I have not had it installed yet - but plan to do so tomorrow. I am wondering if anyone out there knows if this could be the Power Management Device (Not sure of the name -- but I understand in addition to the alternator / battery there is some device that tells the Alternator to put out voltage (I think) -- If anyone has any additional insight with the Power control management device / alternator / battery issues I would greatly appreciate some insight. Thanks

get the right battery first

Originally Posted by Seven11

get the right battery first

^agree the OEM battery are special AGM batteries that differ from the typical Acid/lead batteries.

Originally Posted by csmeance

^agree the OEM battery are special AGM batteries that differ from the typical Acid/lead batteries.

I have always thought that these cars are over engineered....I can understand a non OEM battery causing issue pre start up or during the start up process before the alternator gets going but it weird for a battery to cause issues after the car is started. If all is well technically in the traditional car the battery is just used to start the car. From that point forward it is the alternator powering the car and recharging the battery. The right alternator for a car should be able to produce enough power at idle to electrically power the car. In fact you should be able to disconnect the battery and drive around all day and not need to connect the battery again until you need to start the car.

I have done this in my accord to check if I had a bad alternator but of course I have never tried this with my 7. It would be an interesting experiment.

I just got my '04 745Li back from the shop this evening. It was exhibiting the same issues yours is. While I agree that you need to have the correct battery, the issue with mine was a bad alternator.

Originally Posted by DFEL750I

I have always thought that these cars are over engineered....I can understand a non OEM battery causing issue pre start up or during the start up process before the alternator gets going but it weird for a battery to cause issues after the car is started. If all is well technically in the traditional car the battery is just used to start the car. From that point forward it is the alternator powering the car and recharging the battery. The right alternator for a car should be able to produce enough power at idle to electrically power the car. In fact you should be able to disconnect the battery and drive around all day and not need to connect the battery again until you need to start the car.

I have done this in my accord to check if I had a bad alternator but of course I have never tried this with my 7. It would be an interesting experiment.

AGM batteries are employed for a good owner experience so their car doesn't strand them, and that's to be expected from a car that ranges from 80K to 140K:

Wet Cell (flooded), Gel Cell, and Absorbed Glass Mat (AGM) are various versions of the lead acid battery. The Wet cell comes in two styles; Serviceable and Maintenance free. Both are filled with electrolyte and are basicly the same. I prefer one that I can add water to and check the specific gravity of the electrolyte with a hydrometer. The Gel Cell and the AGM batteries are specialty batteries that typically cost twice as much as a premium wet cell. However they store very well and do not tend to sulfate or degrade as easily as wet cell. There is little chance of a hydrogen gas explosion or corrosion when using these batteries; these are the safest lead acid batteries you can use. Gel Cell and some AGM batteries may require a special charging rate. If you want the best,most versatile type, consideration should be given to the AGM battery for applications such as Marine, RV, Solar, Audio, Power Sports and Stand-By Power just to name a few. If you don't use or operate your equipment daily, AGM batteries will hold their charge better that other types. If you must depend on top-notch battery performance, spend the extra money. Gel Cell batteries still are being sold but AGM batteries are replacing them in most applications. There is a some common confusion regarding AGM batteries because different manufactures call them by different names; some of the more common names are "sealed regulated valve", "dry cell", "non spillable", and "Valve Regulated Lead Acid" batteries. In most cases AGM batteries will give greater life span and greater cycle life than a wet cell battery.

he Absorbed Glass Matt construction allows the electrolyte to be suspended in close proximity with the plates active material. In theory, this enhances both the discharge and recharge efficiency. Common manufacturer applications include high performance engine starting, power sports, deep cycle, solar and storage battery. The larger AGM batteries we sell are typically good deep cycle batteries and they deliver their best life performance if recharged before allowed to drop below the 50% discharge rate.

The reasons above are why the 7's battery can cause such issues. If the battery is at the end of it's life or if the car has the wrong battery, the charging system won't be able to charge it properly and even monitor it properly thus causing voltage spikes, dips and other electrical issues.

Thanks to all -- I won't go into the battery debate but I doubt that ANY non BMW battery won't work; FYI to all, Autozone has an AGM BATTERY in their new platinum line -- at a great price I think it's $159 or $169. it's interesting though that my old and new battery tested bad from the positive block under the hood, where the Autozone guy said it was fine to test from --- at the battery terminals (under the jack) they both test "good" and the charging tested ok at first and then bad --

Originally Posted by el jamon

Thanks to all -- I won't go into the battery debate but I doubt that ANY non BMW battery won't work; FYI to all, Autozone has an AGM BATTERY in their new platinum line -- at a great price I think it's $159 or $169. it's interesting though that my old and new battery tested bad from the positive block under the hood, where the Autozone guy said it was fine to test from --- at the battery terminals (under the jack) they both test "good" and the charging tested ok at first and then bad --

Any AGM battery will work, it doesn't have to be a BMW battery. And as far as those testers go, they are meant to be checked AT THE BATTERY TERMINALS and not the accessory terminals that are under the hood. The ones under the hood go through electronics to monitor if you charge battery with a trickle charger and such and thus cause false readings.

The voltage regulator in the alternator can be a problem, yes, but whether that is the issue can only be found via oscilloscope. It's a hassle, but might not be a bad idea to just let the alternator rebuild guys tell you what's up with it.

Thanks, Keif. I had the rebuilt alternator installed today -- at first everything was fine -- charged at about 13.8 for a while -- then it began to do the old stuff -- spiked up (didn't seem as high ) and set off some of the faults described earlier -- Then, it started only running at about 11.6 - 11.8 volts constantly -- Since I didn't have an AGM battery, I picked up the one at O'reilly's and put it in thinking the other battery had issues (took it back to autozone = I had the non agm one). Same issue -- runs at 11.4 - 11.8 now almost all the time, occasionally sitting in park letting it run for a while you can hear / feel the drag of the alternator kick in and it goes up to 12.6 - 13.2 then it comes back down 11.4 - 11.8 --- To me it seems whatever sends the message to the alternator (engine control module -- maybe?) is sending this Alternator bad information -- is this possible ? I plan to have the battery "registered" to the car tomorrow - and think that may help -- but i doubt it will solve this -- Any thoughts -- I want to trade this car in soon, don't want to screw anyone at all hence the new battery (I think my old one was fine but it was mfr'd in 04') -- but I don't want to put stealer cas$$ into it -- Also -- new error on the passenger restraint fault (reading here i'm pretty sure it's due to low voltage since the battery is draining at the 11.6 - 11.8 voltage charge rate) -- and I hope it will "reset" -- can you reset in the hidden menu?

The power module uses a lot of statistics to determine the state of the battery, and how to charge it, so registering the battery may actually do some good.

+1 ^ your car doestn know you have a new battery or alternator for that matter without registering the battery should proably clean those lights after that good luck and let us know.

Other problem-- ok - I took the old alternator to have it tested - and it tests fine -- it ran 14 volts under varying rpm's and simulated various loads for a good 15-20 minutes --- i did this since the new one didn't fix my problem -- I have a new AGM battery / the fact that the old alternator worked perfectly tells me there is an underlying cause --
On the car with the new alternator, The voltage runs at 13.6 when it's cold -- then once the engine warms up -- it drops to 11.8 ( probably just the voltage of the battery and it continually drops -- no charge only depletion -- ) occasionally it will bounce up to 12.6 volts -- but then back down into the high 11's. Only way to get it to charge again is for the car to be allowed
To completely cool down--- what else can this be?? Power control module? Engine control module? --any ideas?

I was having the same problem with my 03 745Li with 136K miles on it lke El Jamon was having. It was the alternator. The voltage will check good, but it's the diodes in the alternator that's breaking down. For those who do not know, the diodes keeps the electric current produces by the alternator from movng the reverse direction. Take it to a alternator/starter rebuild shop and let them test it.

Thanks for chiming in -- I am taking it to a good diagnostics guy tomorrow to try to figure this out -- it's killing me -- seems like EVERYONE; their problems went away with a new alternator w/ or without a new agm battery -- mine is doing some weird things -- the alternator charges albeit very low when car is cold -- charges between 12.6 and 13.8 -- as soon as the car warms up it goes to about 12 volts then into the 11's so I turn it off as I don't want to drain the battery -- since I had the old alternator tested and it tested fine on a bench - makes me think there is an underlying cause -- ECM? Probably should have put a heat gun on the old alternator to see how it reacted if the voltage regulator was warmed up as it would be down next to the engine block on the car - because it stayed very cool on that bench --- On the car, the new alternator kicks in and out -- you can feel the drag on the engine and when it's "dragging" - the volts are in the high range explained before --. Anyone seen this before? I've checked all the connections that I can get to between the battery and ground / and the power module -- because it sounds like a loose connection but no luck -- Thanks

Here's your problem, seems your not getting it. 1. The battery needs to be registered to the vehicle. 2. The alternator will test good but I can tell you for fact it is probably bad. Mine did the same thing, your getting right now. You should be getting 14volts (constant) when the car is running. Anything else in the 11-12 is too low bro. I would suggest buying a new alternator and replacing it. While your in there replace your belts at the same time. Both alternators are faulty if you ask me. You can get an alternator charge monitor on Amazon for a few bucks and watch it as you drive the vehicle. I had the exact same symptoms, new alternator and was good to go after the change. I also replaced the battery and had both items registered to vehicle.

Here's where I bought
http://cgi.ebay.com/ebaymotors/GENUI...Q5fAccessories

Thanks Japan --I really am getting it -- I just wanted to make sure that no one knew of any other issues at all since my rebuilt alternator did the same like the old one did and before I went deeper on this I have been seeking any other possible cause --.. i agree with you, seems like in the case of nearly everyone their issues have been solved with a new alternator and many with a rebuilt one as well -- I had confidence in that rebuilt alternator -- it was a Valeo and they even showed me all of the original Valeo parts that they put into them -- hence the scouring for another possible cause-- today I had all faults cleared and the new AGM battery registered -- the rebuilt alternator place ordered me a brand new Valeo and am having it drop shipped to my mechanic, it takes 2 days to get here so I will have it put on in two days and totally hope it clears all my issues -- it will arrive on Thursday and I will post the results -- I love these cars -- 7's have always been my favorite car on the road, but I am ready to trade her in -- business is off so I can't get a newer one now and I don't have a place to do my own work which i like to do -- I don't have the time, money or patience to do all of this nor am I willing to go to the stealer --- I have read where stealers have replaced the dynamic stablity control system for this very reason -

Everyone that told me alternador was CORRECT -- Brand New Valeo Alternator arrived yesterday and had It put on today and its a smooth, consistent 13.8 volts. . I had to pay the Labor twice on the alternator -- plus got a new battery -- have a brand new alternator // double labor and new battery + battery registered / codes cleared -- good to go! I guess the rebuild shop is responsible for the second go round on labor?? -- I'll see what I can do I did order the new one through them and they've been good to work with --

glad everything was taken care of!

and if u didnt register the battery and just got a new alternator you would have problems in a couple months

So anything new? everything still running smooth???

I am having the same problem on my 2003 745i. I have had intermittent Trans Failsafe, inactive DSC and Passenger Restraint Airbad errors, generally always in stinking hot weather. Am going to dealer tomorrow to have Alternator tested, new battery installed ( 9 yrs on the original is pretty good, but enough) and the belts replaced if the Alternator needs to be replaced. This thread has been invaluable to me and I will report back with the results, although I will be a lot less rich! Roger

Originally Posted by rogb

I am having the same problem on my 2003 745i. I have had intermittent Trans Failsafe, inactive DSC and Passenger Restraint Airbad errors, generally always in stinking hot weather. Am going to dealer tomorrow to have Alternator tested, new battery installed ( 9 yrs on the original is pretty good, but enough) and the belts replaced if the Alternator needs to be replaced. This thread has been invaluable to me and I will report back with the results, although I will be a lot less rich! Roger

Did you get yours fixed? If so, what was issue?

How do you get the voltage to show?

Originally Posted by markandersonus

Did you get yours fixed? If so, what was issue?

My car's problem was it needed a new RMFD switch centre and I had a SZL failure....some sort of switch down in the steering column that seems to control many functions. I do not understand it fully , only that it cost me $1300 (part and labour). All codes were cleared and I have had no problems since. I also had a new battery installed, but it was found that the last time the 90AH battery was renewed the battery was not 'registered' and the registration was for a 110AH Lead battery. A programming retrofit had never been performed in CAS module. I don't profess to understand all this, I am just reporting it to everyone.

Originally Posted by rogb

My car's problem was it needed a new RMFD switch centre and I had a SZL failure....some sort of switch down in the steering column that seems to control many functions. I do not understand it fully , only that it cost me $1300 (part and labour). All codes were cleared and I have had no problems since. I also had a new battery installed, but it was found that the last time the 90AH battery was renewed the battery was not 'registered' and the registration was for a 110AH Lead battery. A programming retrofit had never been performed in CAS module. I don't profess to understand all this, I am just reporting it to everyone.

Thanks