Recently my 2008 BMW M6 Coupe gave me the following errors: EDC malfunction, DSC malfunction, Start-off assistance, DBC malfunction. This is the 1st time I am getting these errors.
Have any of you had these errors before? What kind of repairs do you think I might need to fix this? How much money would you estimate these repairs might cost (I understand this is just a guess)? I am just trying to figure out how skewed I might be here.
I have had the errors for a few days, and they come and go. In the morning, when I start the car for the 1st time the errors are gone, and I get a “All systems are okay”. At this time I am able to switch between comfort EDC mode to Sport stiff EDC mode successfully with no problems. But after about 20 mins of driving these error reappear.
Earlier this year I had the Dinan Stage 2 suspension installed on my car. I am scheduled to take my car to the same shop to have them fix this.
Also, recently my battery has been running low. About 2 months ago, after a 1 week long business trip away, upon starting the M6 it warned me that the battery voltage was low. Eventually after driving the car around for 30 mins the warning went away.
Honestly, driving around town with these errors, the car seems fine and safe. So it will be hard to justify spending a lot of money (like over ~$2000) on this repair, but we will see.
I was suspecting the battery for a couple days also. But in the morning the errors on the car go away, and the check on the car says "All Systems Okay". And only after 20 mins of driving do those errors reappear.
Hopefully it is just the battery, which should not be too expensive to replace (anyways battery replacement is part of regular maintanance on the car).
I am betting your battery is going dead as well. Replace ASAP before you get stranded somewhere and will need a flatbed as the car wont start anymore.
Driving the car for 30 minutes will make the fault messages go away because the alternator takes over once the car is started.
I have a post on here on how to replace the battery and with what aftermarket brand that works great and fits well.
Battery life on our beast is good for around 4 - 5 years. I highly recommend replace it preventively to avoid throwing fault codes or car will no longer start one day as battery will no longer hold a charge and not enough reserve to start the car.
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No matter what the cause of your errors, deal with the low voltage problem first.
I agree with Clyde, look up steering angle sensor errors with the diagnostic tool and see what faults come up first. Then check your battery and alternator. There are numerous threads regarding the SZL (steering angle sensor) on here.
I've had everything in the list above replaced on my beast. You need to get a proper scan done to identify the specific cause. You have 2 throttle actuators and 2 idle actuators, 1 on each bank. I went through major issues getting the correct one diagnosed. You can swap them from side to side to see if the faults move to the other bank.
Good luck, update this thread with the repair for others in the future.