[Alex06M5]

Is the wiring insulation cracking? You may have an intermittent short on the wires going to the rack sensor. I know mine is cracking, reminds me of the smg gps harnesses ugh...

the car starts right up no problem runs fine and drives fine only thing is I lose power steering when I drive it with a Servtronic malfunction. I can start the car and let it sit running with it completely still and it will just randomly throw a Servtronic malfunction code and no one has touch the car or turned the wheel. It’s extremely weird. I also checked for voltage fluctuations when the malfunction occurs the voltage does not fluctuate at all.

 

[Alex06M5]

By doing this way you just monitored the system voltage, what you need to monitor is voltage fluctuation at the servotronic sensor itself, access the KGM control unit and navigate to servotronic live data and see what happen to the sensor voltage when the malfunction occurs. May be wiggle the wiring and check.
If not the wiring could be the sensor on the steering rack. Could you access the 93C1 fault to see the details to troubleshoot it better. Could be the sensor has intermittent failure.
It is advised also to access other faults after a deletion and see if it help understand what's going on or if related.

When I try to access the KGM module on the scanner it tells me the ECU could not be read. When I look up the code 93C1 for BMW it comes up with an airbag restraint. But my scanner is saying it’s a Servtronic hardware faulty I also get the codes A0C1, A559, along with 93C1. I have wiggled every single wire underneath the car that has to do with steering it has not thrown any codes it just randomly does it. Right now I have the car sitting on the lift it’s been running for about 20 minutes and just randomly threw the code again.

 

[Alex06M5]

NO, fault 93C1 is the correct fault code for servotronic on this platform. Many information on the internet or other forums are not compatible here.

Get another BMW scanner to confirm the accessibility. Try INPA. Also disconnect the servotronic sensor connector and try to access KGM again.

Could get details if you navigate the fault in this scanner, we need the details.
Does these fault trigger together, delete the faults and test. This will tell us if the sensor is bad or something else cause the issue.

It was getting late and dark but I opened up INPA and give it a shot quick. I did not get to unplug the sensor as you asked I will have to give it a shot when I get some time. Busy during the week. This is what I got from INPA. Even with INPA I was not able to access the active steering category in INPA, one of the pictures above shows the error message I received when I tried to access it. When I checked the steering angle values the ignition was on and the motor was off. I store the car for most of the winter I noticed after I took it out of storage that this was happening more and more. when it was in storage I would start it and drive it when the roads were clear for about a half hour or so. Last summer I did a new clutch, new fly wheel, rod bearings and vanos line. The car did this to me one time when I first bought it 2 years ago, I shut it off started back up and it never came back again. After I did the work to it I also did not have any problems with the steering until now. It has a brand new battery as I in it as I mentioned earlier I just put it in 2 days ago cause it was under warranty and I read that voltage could have something to do with this. I believe it was not the battery sense I’m still having the same issue. Just trying to give you as much info as I can. Thank you guys for the help

 

[Alex06M5]

You are accessing the wrong modules.
You need to access the KGM module to show the live data of the servotronic sensor and the fault details. You need to choose BODY from INPA left menu then I think one of the 2 most bottom modules is the KGM on the right menu.
For the other faults you listed you need to access CAS "Car access system" also under body.

Did what exactly? servotronic failure?.

Yes the servtronic failure happened one time when I first bought it and never had any more issues till now. Tomorrow morning I will have some time to further diagnose the car. I will try and access the correct module to get all the info you asked for. Thank you again for your help I appreciate it. I will post more information tomorrow morning.

 

[Alex06M5]

Hmm, this would indicate replacing the sensor may not solve the issue. The search now is to find out if the system power interrupts the sensor operation to isolate the issue at the sensor or the steering rack.

There is a sensor near the steering shaft on the rack that I believed was the problem from the research I did. So that being said I ordered a used sensor that was tested and in guaranteed good working condition. That’s 2 sensors that where in the car and it’s doing the same exact thing, random (servtronic malfunction) that happens often. There is only one sensor on the rack and pinion right?

 

[Alex06M5]

You are accessing the wrong modules.
You need to access the KGM module to show the live data of the servotronic sensor and the fault details. You need to choose BODY from INPA left menu then I think one of the 2 most bottom modules is the KGM on the right menu.
For the other faults you listed you need to access CAS "Car access system" also under body.

There are two modules listed under body central gateway module and chassis gateway module I cannot access either of them with INPA I receive error messages when I try to enter them through INPA. The same thing happened to me when I try to use a snap on scanner to enter the module it would not connect to the module. I don’t believe this is normal is it?

 

[Alex06M5]

So earlier I went into all control modules and read the fault memory here’s what I received.

 

[Alex06M5]

After I documented all the codes that were in there i cleared them and I’ve had the car running for about two hours now and drove it for about 45 minutes to an hour. I then scanned it again with INPA and these are the trouble codes I received. I have not received a Servtronic malfunction in the I drive control message sense I cleared the codes. For the 520a code I tried to re set the steering angle and I can not access the active steering under chassis or body. I also get an error message.

 

[Alex06M5]

OK we lost the evidence by deleting, wait until it comes up again.
Delete this INPA and download INPA (BMW Standard Tool) it comes with an installer from bimmergeek.com, this one is missing some files. You should access the KGM but missing its file.ipo. You need to access to see the details of the fault and diagnose better.

Ok thank you for your help. When I get home I will go on Beamer geeks and download the newest version.

 

[Alex06M5]

No it doesn't reflect the mechanical turn angle. The steering angel sensor measure the steering wheel rotation degree of 440 to the right and 440 to the left which equal to 2 turn and 1/3 from lock to lock, the wheel and tire turn 45 degree approximately in response.

I don't think the system uses the steering angle sensor to test plausibility in term of servotronic, this evaluation check doesn't exist simply because there is no fault code for it. The code in this case is hardware failure and this can be caused by electrical or power issue or failed control unit internal circuitry (KGM). In addition, there is no feed back signal from the steering hydraulic flow, servo sensor or the steering mechanical angle, the steering angle sensor signal doesn't reflect the actual mechanical turn angle. The car system (DSC) will accept steering wheel deviation during the calibration process up to certain degree. In other word, if you disconnect the steering shaft from the rack input shaft and turned the steering wheel and tried to calibrate the steering sensor the system will take it.

So I believe the car is all set with the steering issues last Wednesday I cleared all the codes and reset steering to 0°. have been driving it since last Wednesday I put about 350 miles on it no steering issues. I appreciate all your help I believe in my scenario I just needed to readapted servtronic sensor. Knock on wood I will let you know if anything changes.
Ps. I recently noticed some rough idle coltstart issues I will be starting a thread on if you guys care to chime in. thank you again.