U0002 U0146 U0121 U0155 P2158
Got these codes and car runs fine but then after just sitting in park slip lights come on dash and occasionally check again light. Turn the car off and light go away. Loses power when it happens and speedometer needle starts jumping and rpm's kind of sputters. I sanded grounds battery seems good alternator also good found some blown fuses but I replaced them. It starts acting up randomly it originally started last week when it wasn't coming out of park or turning on but I boost the battery with battery pack and it turned right on, but since then it's been really weird. Any help please on what it can be thanks in advance.

 

moved to W204 forum...

 

Which OBD scanner are you using, a Mercedes specific scanner or generic?

Have you had the battery and alternator tested? How old is the battery? have you tried to fully charge the battery?

- P2158 "Vehicle Speed Sensor B". I think it is near or in the transmission.

- U0146 Lost communication with Gateway A.

- U0121 Communication with ABS module. In a thread I recently read the fix was having the ABS module repaired: https://mbworld.org/forums/cls-coupe...0121-code.html

* Here's an interesting thread where someone had P2158 and U0121, they said it ended up being water getting in the car: https://mbworld.org/forums/c-class-w...158-u0121.html

* Here's an interesting thread on the U0155, they claim it was caused by a bad battery in the key fob. I did not think the battery in the key fob would cause any issues other than the car not unlocking/locking, but worth a shot: https://mbworld.org/forums/e-class-w...e-what-do.html

I'm still curious what scanner you are using.

 

Yea definitely was a generic one but I did notice water under the passenger and driver carpet but it doesn't look as crazy as I've seen online. I was wondering if it would be ok to dry and clean it up and maybe it'll get better. Or would I have to change everything regardless smh. Also found these but idk if it is related to my issues.

Smh the black is grounded/bolted to the floor.

 

I would pull up the carpet and try and dry everything out. Only takes a small amount of moisture to cause electrical problems. Especially with connectors, a little bit or corrosion causes things to short out.

May be worth buying a Mercedes specific OBD scanner.

 

Dried everything I even took out the seats and carpets found a little of corrosion on the little communication boxes sanded all the grounds and let it dry. I even took out the front Sam module and it was not wet at all in there and it actually looked like it was in fantastic shape. Also got my passenger seat moving again it was a missing fuse in the trunk and another blown fuse. Everything was fine then after sitting a while lights come back on smfh. I'm at a shop now to see what they say.