Mercedes-Benz Non Start &/Or Eco Stop/Start Not Working.

Technical Article
POSTED 25 September 2023

Mercedes-Benz Non Start &/Or Eco Stop/Start Not Working.

Models Affected

  • Mercedes-Benz C Class 205

Model Years Affectedshutterstock_1047502279

  • 2014-2016


  • Vehicle may not start intermittently.
  • May display “start engine" message on infotainment, when engine is already running.
  • Eco stop/start may not work.

Associated Fault Codes

  • Voltage below threshold in most modules.
  • Voltage above threshold in the front sam.

Possible Causes

  • Battery sensor and earth lead.
  • Battery fault.

Test Steps

Tests for eco stop/start not working

1. Check battery condition and age. On a genuine Mercedes-Benz battery the production date is stamped onto the negative pole of the battery, it is made up of 4 numerical digits.

The top two are the week produced, the bottom two digits are the year of production the picture below shows week 43 2013.


2. Check battery sensors make. If it is a Hyundai Mobis part number A 0009050554, this would need changing for the new modified type as the battery state is not calculated correctly.


The modified battery lead is A0009056507 pictured above on the right.

Test/checking procedure for intermittent non start or star engine on Comand screen when engine already running.



This may be caused by high resistance at the body connection of the earth point on the passenger inner wing.


Remove the battery earth lead, and check the connection is tight.

Also check for burn marks to the terminal as seen circled below. If burn marks are found please replace the battery lead and clean/ replace earth stud on inner wing.



Tools Required

  • Various hand tools
  • Battery tester


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