Whys this happening
Thread Starter
Newbie
Joined: Apr 2018
Posts: 3
Likes: 0
09 c300
Whys this happening
So at idle my head light icon and my brake icon along with my airbag light will randomly flash id like to get it fixed before it causes a real issue i have a video ill add to post after work
Super Member
Joined: Jun 2017
Posts: 608
Likes: 107
From: Western NC
2009 MB C300 Sport 4matic
Ah Electrics !! I'd start with the easy multimeter check of the battery (static, OFF = 12.4-8 volts, nice if higher but unlikely) and check at idle, a 14.0-14.4 V. Add some Info on your Benz.. miles, R&R work done that relates to the charging system Do the flashing icons show right up at Start or ING ON or appear after some delay while idling ? A Search(Google, not just MB Forum) of this problem will yield several cars/posts with similar/same problem and explanations/ solutions all over the place...IGN switch, front SAM module ,poor ground related usually in old/salt /winter road run cars, even the brake pedal light switch, and others
Welcome to the Board.
Welcome to the Board.
Thread Starter
Newbie
Joined: Apr 2018
Posts: 3
Likes: 0
09 c300
Its a 09 c300 183k miles it was a California then went to texas now its in oklahoma im the 3rd owner and its been maintained by mb dealers only its whole life was a old fleet car it only happens when its at idle i noticed it drop alittle in rpm i did have to jump it the other nightit was super cold out it possibly needs a new battery i sit in my car at lunch and it didnt flash at all but some times when i shut off the car the upper eye browl light on one side will stay on and i have to touch the light switch could this be related?
Super Member
Joined: Jun 2017
Posts: 608
Likes: 107
From: Western NC
2009 MB C300 Sport 4matic
Things seem to be pointing towards a new battery if your present one passes a load test, or just get a new one. If the parking fore/aft lights are left on long enough and enough times that can certainly put that last bit of stress on an already end of life battery. leave the headlight switch on "A" and you'll be less likely to accidentally leave the "curb" lights on.
Thread Starter
Newbie
Joined: Apr 2018
Posts: 3
Likes: 0
09 c300
Yeah i thought it would be the battery with the way the weather has been flucating from 70s down to the 40s every other day got to looking at it looks like the date on the battery is from 2012 so its long over due for a new one i was just concerned that it could have been in some of the flooding that happened in texas a few months ago and im still in the buy back warranty time frame thank you for the info ill test the battery and return with the results
