Turned on my 2012 GLK350 this morning after a particularly cold evening (-10 celcius) and there was considerably more vibration coming from the engine than normal. The check engine light blinked and then was solid. I thought that maybe the engine just needed to warm up... but it persisted for nearly an hour of driving. When I finally parked, turned off the engine, and then re-started it, the light was then gone, but the error codes from my ODBII scanner remained. Anyone got a hunch on what's going on here? I'll be replacing the spark plugs when they arrive in the mail, but the voltage, steering, and clutch stuff has me thrown...

Car Scanner ELM OBD2
DTC report
Selected brand: Mercedes-Benz

============1==============
P0810
Raw code: 0810
ECU: Engine control unit
Status: Pending fault present during this driving cycle, Validated and stored in non volatile memory
OBDII: Clutch position control error
Mercedes-Benz: Clutch Position Control Malfunction

============2==============
P0641
Raw code: 0641
ECU: Engine control unit
Status: Pending fault present, Validated and stored in non volatile memory, Validated fault present at time of request
OBDII: Sensor reference voltage A - open circuit

============3==============
P0636
Raw code: 0636
ECU: Engine control unit
Status: Test is inhibited by other DTC, Validated and stored in non volatile memory, Validated fault present at time of request
OBDII: Power steering control - circuit low

============4==============
P0629
Raw code: 0629
ECU: Engine control unit
Status: Pending fault present, Validated and stored in non volatile memory, Validated fault present at time of request
OBDII: Fuel pump (FP) control - circuit high

============5==============
P0303
Raw code: 0303
ECU: Engine control unit
Status: Pending
OBDII: Cylinder 3 - misfire detected

============6==============
P0301
Raw code: 0301
ECU: Engine control unit
Status: Pending
OBDII: Cylinder 1 - misfire detected

============7==============
P0300
Raw code: 0300
ECU: Engine control unit
Status: Pending
OBDII: Random/multiple cylinder(s) - misfire detected

 

That smells like a voltage issue to me.

 

How old is the battery ?

 

Battery

 

I think you guys might be right. I plugged in a dash camera (Viofo a119) and it stopped charging/turning on a few months back. I hadn't had to the time to find the problem, but it might be the battery is weak.

I've got a Battery Tender; do you think this will help for a while or at least get me through a cold winter? What's the standard procedure for testing and/or replacing the battery?

 

How old is the battery, if it’s 2012 just replace it with An AGM, a tender won’t help a dying battery, Any auto parts store will test it free. If you have a volt meter that will give an indication of condition . An old battery can ruin your cars computers and more, don’t keep a weak battery .

 

Replace the battery. Batteries are expendable and have finite lives. It's time for a new one.

 

Thanks guys. I bought the Energizer H6 AGM Battery from Costco. It was exactly the same size as the old battery, which turned out to be in really rough shape. The check engine light is now off, but the ODBII error codes still show up, even after I clear them while the engine is off (ignition is on). It certainly drives better, with less vibration, and smoother steering.

Does the 2012 GLK 350 have an auxiliary battery like the 2013 and newer models? I checked in the back by the spare tire but there wasn't a battery there...

I'm asking because the dash cam that I installed is wired to the fuse box under the backseat (i.e. not the one under the engine bonnet). It wont turn on/charge, which leads me to think that maybe there's an auxiliary battery for that fuse box that's dead. Anyone know?

 

If you have ( the annoying ) auto Stop Start you have the extra battery , a bad main battery caused my power amp to glitch where I had to to remove its fuse to reset it, many times, until I got a new battery,