I have a 08gl320, and my engine light came on couple of days ago. I checked the code and it read '2306 sensor supply voltage 2, the signal voltage is too low. I thought it might be the battery so i did a test on the battery and it passed the test. i was wondering if someone can update me on this, thanks.

ps: it came on after 1 whole day of just being parked in -10C, and as i started it the engine light was on

 

What type of test did you perform on the battery? How old is the battery?

Has it been fine, since? Clear the code and see if it comes back.

 

i m sorry for the late reply, but this is what i did,
- first when it came on i check the code delete it and drove the car for quite a while just to charge the battery. the next day when my dad drove the car to work and it was fine but when he was coming back after 9hrs shift the light came back on again.
- this time i took it to my work, i work at a subaru dealership (i drive a subaru too), i use one of the subaru electrical diagnosis system to charge the and test the battery. it told me the battery was good and topped it up. but the engine light was still on.
- now this time i was like i need to spend money and take it to mercedes to get it checked and install a new battery. but while i was driving it, miraculously the light went away next morning.
- this is now the second day the light hasn't came back on, if it will i will keep you guys updated.

 

Either your fuel pressure sensor is going bad or the harness attached to it/ plug is bad.