Hyper_545i

Hello All,

Yesterday driving into work, I get a message on my iDrive stating "Dynamic Drive Mafunction". I got to work, shut the car off and restarted. No error. I checked the Check Controls and nothing was reported so I figured it was just a fluke thing. I left work and got to about 5 miles from home when I got the error again! After searching the forum (yes I searched first ) I found it could be a couple of things. Hoping with the easiest and cheapest, I checked my power steering resevoir. I am a bit embarassed but, I had a hard time reading the hash marks.

Can anyone tell me what the MAX and MIN are on the dipstick. I see MAX and rigfht below it is a mark. I want to say the line is for the MIN as there is a hashed out area both from the bottom of the stick to above the MAX mark. MAX is written on the middle of the dipstick. I suspect it could be low, it's been a bit cool at night here in Jersey the last few days and suspect this is the culprit. I checked it this morning before starting the car and it was at this line below MAX. Don't know if that means its full or at the minimum.

I unlocked the Voltage Meter and have been watching the voltage. I am between 14.2 and 14.5V while cruising at highway speeds. Battery is in good shape. I suspect the alternator is ok as well from my findings.

Thank you in advance!

BimmerFan52

You were smart to check the alternator and battery. The 545i needs huge amounts of current at the correct voltage and anytime I get a system warning I sniff around the battery/alternator/ground system. Make sure you check the battery before starting and watch to voltmeter just after starting. My alternator voltage regulator started to go and would output a very high voltage for the first minute and then settle down.

Sounds like your cap might be a little different from mine. The stick built into my power steering reservoir cap has a max line but no min (the bottom of the stick is the min) and if there is no fluid on the very bottom of the stick then I am below the min. This may be because my reservoir was replaced last year when my steering rack was removed and reinstalled. Because I needed new fluid I decided to have a new reservoir put in (filter is built into the bottom of the reservoir).

When I have had low fluid in the past my error was Active Steering malfunction, not dynamic drive, but who knows with these complicated monsters. You might want to top it off and see if the error goes away permanently.

If you need to fill, use Pentosin CHF 11S only, not ATF. About $15 for a litre can.

deansimpson

I have had the same issue for the last year.
It randomly comes up from time to time and always goes away after re starting the car.
No codes or errors.
My P/S fluid level is fine and my battery is fairly new and my voltage is fine.
Sounds like we're in the same boat. I hope someone figures this out!

Hyper_545i

BimmerFan52,

Thank you for the reply. I checked the PS Fluid and it it a hair under the MAX mark, so I suspect that is fine. The fluid is very clean as well. I did not get the error this morning. I'm heading home soon so we will see how that goes. It was unusually cold this past weekend. Wondering if that has anything to do with it. Maybe it was a "glitch". I guess time will tell. I'm hoping it is not something serious. The fact that turning off the car and restarting seems to clear the error, hoping it is not severe.

deansimpson,

Now I'm concerned if your has been happening off/on for a year. Sounds like we are in the same boat.