Mercedes electrical problems and common fault codes


Mercedes electrical problems can affect up to 80% of the operation of other systems in the car. What are the common electrical problems, how to fix them and how much does it cost? All this important information will be shared by Eurocartool experts in the article below.

Mercedes electrical problems reason

The electrical system is a complex structure, and when you encounter a problem, it will be difficult to diagnose accurately. Below are some common errors listed by our experts.

  • Weak or damaged battery: A weak battery can cause problems such as difficult starting or other electronic systems not functioning properly.


  • Burned Fuse: Burned fuses or overcurrent protection can cause loss of power to electrical systems and equipment, leading to loss of functionality of many devices.
  • Faulty Alternator: A charger that is not working properly can cause the battery to not be fully charged, leading to a weak battery or running out of power.
  • Damaged rear view mirror sensors and mirror lights: The sensors in the rearview mirror or mirror lights may have problems, causing loss of warning or automatic adjustment functions.
  • Broken lighting system: Errors in lighting systems such as headlights, taillights, or turn signals can cause safety risks and violate traffic regulations.
  • Loss of power window and door function: Faults in the power window or door system can cause them to become inoperable or jam.
  • Door lock and security system errors: The automatic door lock system, alarm system or anti-theft system may have problems causing loss of function or false alarms.
  • Air conditioning and heating system faults: Faults in the air conditioning or heating system can cause discomfort while driving.


  • Information and entertainment system (Infotainment) failure: Failure in the audio system, touch screen, GPS, or entertainment functions may cause loss of entertainment function and result in the inability to use the features connect.
  • Lost connection to the diagnostic device (OBD-II port): When the ECU cannot be connected via the OBD-II port, error code reading and diagnostics will be limited.

Diagnose Mercedes electrical fault codes

Mercedes electrical problems related to the electrical system will have a number of common error codes that are diagnosed through professional diagnostic equipment. These include:

  • P0100 – Mass or Volume Air Flow Circuit Malfunction: Error in the air flow or mass air flow measurement circuit.
  • P0300 – Random/Multiple Cylinder Misfire Detected: A problem occurs during the ignition of one or more cylinders.
  • P0420 – Catalyst System Efficiency Below Threshold (Bank 1): The catalytic system is not operating effectively.
  • P0500 – Vehicle Speed ​​Sensor Malfunction: Vehicle speed sensor error.
  • P0600 – Serial Communication Link Malfunction: Error in the communication circuit between electronic modules.
  • P0700 – Transmission Control System Malfunction: Error in the transmission control system.
  • P1230 – Fuel Pump Relay Malfunction: Error in fuel pump relay.
  • C1014 – CAN Communication With Traction System: CAN communication error with traction control system.
  • B1000 – Control Module Malfunction: Error in the control module.


  • U0100 – Lost Communication with ECM/PCM: Lost communication with ECU/PCM (Engine Control Unit/Powertrain Control Module).
  • U0155 – Lost Communication with Instrument Panel Cluster: Lost communication with the meter display.
  • U0402 – Invalid Data Received from Transmission Control Module: Invalid data received from the transmission control module.

Some simple fixes Mercedes electrical problems

Step 1: Diagnose the cause: You can use Xentry software to diagnose all vehicle systems in-depth and quickly.

All Mercedes electrical problems in the electrical system come from the battery, generator and starter. If one of these components fails, you will not be able to start your Mercedes-Benz. There are also some problems such as blown fuses, poor electrical connections,…
You can use professional diagnostic equipment to search for error codes and error locations more accurately.

Step 2:
If it is a mechanical problem, replace or repair the damaged component. Note that you need to disconnect the battery before proceeding and reconnect it when the repair is complete.
If it is a software error in the operating parts, use specialized equipment and software to perform programming and recording so that it operates normally again.

Step 3: Check and maintain the entire electrical system
Check the battery load level, clean and test all terminals to complete the repair process.

To be able to accurately repair error codes, you should use WIS/ARSA or Starfinder software to look up detailed circuit diagrams. From there, make an accurate repair plan, helping you save time during the implementation process.

Mercedes electrical problems are an important issue and require careful steps to resolve. It’s best to ask experienced repairmen like Eurocartool experts. Contact WhatsApp: +13155472355 for free consultation.

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