I accidentally left my lights on yesterday morning. After work, I came out to a dead battery. I jumped the car with my friend's truck. After about 10 minutes of driving all my features were back up and running. The car starts fine and the batteries were replaced in 2012.

Only issue is that my steering wheel controls, horn and shift buttons do not work. Basically, everything on my steering wheel is dead. Everything else in the car works.

Any ideas?

 

Put the car on a charger to fully top up the battery, minimum over night. A lot of issues are a result of a less than optimal battery. The car is "smart" enough to reroute power so this is where I would start.

 

OK. It won't hurt to try that. I called a Benz tech and he said it sounds like a steering wheel control module. With my luck, his diagnosis will be correct but I will try charging it anyways.

Thanks for the idea.

 

hey mike, how you doing man? when you get it all charged, unhook the negative side of battery post for a few minutes, just remove it and put it back on. sometimes when the battery have completely died in these cars, unhooking the battery sometimes seem to "reset" everything. wont hurt anything and it will only take a few minutes. i will call you later on wednesday and see how you coming along. take care.

 

Yes, sometimes a battery reset will help but you will need to reset all your window, sunroof and steering wheel once battery is un-hooked. The best way, is to find someone with STAR, read all the codes and do a reset with star.

 

Just wanted to follow up with this. I unplugged the negative terminal for about 5 minutes. Hooked it back up and everything works again; horn, radio controls and paddle shifters.

I guess I got lucky because I didn't have to mess with my windows or sunroof. Just the radio presets.

Al, thanks again buddy.

 

I have this problem but it keeps coming back a few days after I fix it by unplugging the battery for awhile. Any ideas?

 

I seem to have resolved the issue by leaving the battery unplugged over night. Noticed 10 min lasted more than 30 second disconnect so attempted full discharge of cat electricals

 

Interesting.