DavidF

First off, yes, I have done many searches. Can't really find quidance after doing searches.

So, new to me 2004 545i. Periodically got the dynamic drive fault, active steering, and roll stabilization faults. Restart cleared them right up. Then, active steering malfunction set permanently along with steering wheel off center. I have ensure full battery charge, topped-off hydraulic fluid, and reinitialized active steering. Nothing worked. Stumped.

Also, it seems my charging system is behaving erratically. Often, at idle, I can hear the alternator engage and disengage rhythmically with corresponding change in idle speed (assumed to be function of alternator apply load on and off). Monitoring the battery/system voltage while this is happening shows around 12V sometimes abit more sometime abit less. When the issue stops, I get 13.5V or higher (what I would expect with properly functioning system). So, my immediate thoughts are this is the cause of the active steering fault. But with battery charger connected (and thus adequate voltage) the active steerign will not reset.

Everything else in the car works properly with no indicated faults.

My question: What to check next? If SZL is faulty, wouldn't I get a DSC warning due to no steering angle input? Power Management module or voltage regulator faulty (causing alternator issues)? All advice appreciated. My next step will be to connect INPA and read stored fault codes, just have not been home during daylight hours for the past two weeks...ugh.

Thanks for any advice, in advance.

545felix

i've been trying to tackle this one too. I found the valve cover gasket on the driver's side is leaking oil onto my 4-month old alternator. I'm going to clean all the oil off this weekend to see if that does anything to improve it. The front active roll motor is coated in old grease and dirt, I'm going to clean that off and check the connector as well to see if that's part of the problem. I replaced the charging relay in the trunk and that didn't fix it either.

As with yours, problem disappears after a restart and doesn't show up until the next really cold (sitting for at least 8 hours) start.

Another thing I'm suspecting is the MPM.

I don't have a single fault code stored, even with all the dynamic drive faults showing on the screen. fortunately i haven't had any problems with the active steering.

Ballistic

afaik.. The alternator does not engage/disengage, Its always on. Charging voltage should be above 14volts i believe.

My guess is the battery and/or alternator. The voltage level should be higher then 12volts, even when just ideling.

SilberGrauE60

Check the hydraulic fluid (CHF-11S) reservoir...

545felix

Ballistic, it's always running on NORMAL cars. the E60, the alternator's output is controlled by a charging relay in the trunk that is activated by one of the many control modules. it's cut off at certain times to increase fuel economy.

i'm getting 17 freaking MPG so you can guess how well that's working....

545felix

topped off weeks ago. no change.

DavidF

Appreciat all the comments so far. I need to dig deeper than all the easy things to check as I have done them all.

So, should alternator engage and disengage several times in the span of one minute? I am guessing not. Does this mean voltage regulator fault or power module fault? I think that once I get the power cleaned up, I can tackle the active steering.

healthservices

Are you sure it is not the ac compressor engaging and dis engaging? As mention the voltage should be higher about 14.3-14.7 when running

DavidF

The HVAC system is off. I can hear (just listening and using stethoscope) that the alternator is cycling between load and no load. When it is doing this, the indicated voltage at battery charge post under hood is too low. I have measured 11.9V occassionally, but mostly just around 12V (which is lower than static charge on battery). Once the alternator load/no load cycling stops, I get a higher voltage reading of approximately 13.5V (which should be within normal acceptable range). Again, i am guessing this is abnormal behavior. The battery has never gone flat to the point of starting the engine.

So, to recap:
Hydraulic fluid level is good.
Reinitializing active steering does NOT work.
Multiple restarts does not clear faults (even with battery connected).
Alternator behaving erractically.
No other fault messages other than "Active Steering Malfunction"

healthservices

I'd start off by charging the battery and having it checked out. Then I would go to the alternator afterwards as it is reading too low. this is mine under the hood.

14.31-14.9




Low voltage will do a lot of wack things, and give you a lot of error codes. What does the voltage do when you have the lights and accessories on?