Fault code lookup

Mercedes-Benz fault codes

20,291 codes · 1,724 vehicle records · 258 ECU records · 56,350 live-data parameters

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Codes 20,291

CodeDescriptionBrandsSystem
B121207Der Stellmotor für Luftverteilungsklappe vorn links hat Funktionsstörung. Es liegt ein mechanischer Fehler vor.2Body
B121249The actuator motor for the left front air distribution flap has a malfunction. There is an internal electrical fault.1Body
B121251Der Stellmotor für Luftverteilungsklappe vorn links hat Funktionsstörung. Das Bauteil ist nicht programmiert.1Body
B121287Der Stellmotor für Luftverteilungsklappe vorn links hat Funktionsstörung. Botschaft fehlt.2Body
B1213PTC heating component fault22Body
B121349The actuator motor for the right front air distribution flap has a malfunction. There is an internal electrical fault.1Body
B121351Der Stellmotor für Luftverteilungsklappe vorn rechts hat Funktionsstörung. Das Bauteil ist nicht programmiert.1Body
B121387Der Stellmotor für Luftverteilungsklappe vorn rechts hat Funktionsstörung. Botschaft fehlt.1Body
B1214Passenger Seatbelt Retractor Pretensioner Deployment Control21Body
B121449The actuator motor for the left rear air distribution flap has a malfunction. There is an internal electrical fault.1Body
B121451The actuator motor for the left rear air distribution flap has a malfunction. The component is not programmed.1Body
B121487Der Stellmotor für Luftverteilungsklappe hinten links hat Funktionsstörung. Botschaft fehlt.1Body
B1215External Memory Card22Body
B121549The actuator motor for the right rear air distribution flap has a malfunction. There is an internal electrical fault.1Body
B121551The actuator motor for the right rear air distribution flap has a malfunction. The component is not programmed.1Body
B121587Der Stellmotor für Luftverteilungsklappe hinten rechts hat Funktionsstörung. Botschaft fehlt.1Body
B1216Tailgate latch close microswitch19Body
B1217Passive Key-in Ignition Output19Body
B1218No data flow in electronic stability program18Body
B1219Semi-automatic parking system electric power steering (EPS) status information failure19Body
B121987The electrical fine particle filter has a malfunction. The message is missing.1Body
B121AKeypad Illumination Output16Body
B121A07Electrical expansion valve 'Heat exchanger for cooling the high-voltage battery' has a malfunction. There is a mechanical fault.1Body
B121A49Electrical expansion valve 'Heat exchanger for cooling the high-voltage battery' has a malfunction. There is an internal electrical fault.1Body
B121A87Electrical expansion valve 'Heat exchanger for cooling the high-voltage battery' has a malfunction. The message is missing.1Body
B121A98Electrical expansion valve 'Heat exchanger for cooling the high-voltage battery' has a malfunction. The component or the system has overtemperature.1Body
B121B49Electrical expansion valve 'Exterior heat exchanger' has a malfunction. There is an internal electrical fault.1Body
B121B87Electrical expansion valve 'Exterior heat exchanger' has a malfunction. The message is missing.1Body
B121B98Electrical expansion valve 'Exterior heat exchanger' has a malfunction. The component or the system has overtemperature.1Body
B121C49The actuator motor for air flap 'Central air vent' has a malfunction. There is an internal electrical fault.2Body
B121C51The actuator motor for air flap 'Central air vent' has a malfunction. The component is not programmed.1Body
B121C79The actuator motor for air flap 'Central air vent' has a malfunction. The mechanical connection has failed.1Body
B121DRear HVAC Mode Control Input15Body
B121D64Current sensor 1 of the refrigerant compressor has a malfunction. There is an implausible signal.2Body
B121EMute Switch11Body
B121E49Current sensor 2 of the refrigerant compressor has a malfunction. There is an internal electrical fault.1Body
B121E64Current sensor 2 of the refrigerant compressor has a malfunction. There is an implausible signal.1Body
B121FAutomatic vehicle speed adjustment request status and received information failure11Body
B121F49Voltage sensor 1 of the refrigerant compressor has a malfunction. There is an internal electrical fault.1Body
B121F64Voltage sensor 1 of the refrigerant compressor has a malfunction. There is an implausible signal.1Body
B1220Hydraulic Proportional Valve22Body
B122049Voltage sensor 2 of the refrigerant compressor has a malfunction. There is an internal electrical fault.1Body
B122064Voltage sensor 2 of the refrigerant compressor has a malfunction. There is an implausible signal.1Body
B1221Internal left front parking assist sensor failure23Body
B122149Temperature sensor 1 of the refrigerant compressor has a malfunction. There is an internal electrical fault.1Body
B122164Temperature sensor 1 of the refrigerant compressor has a malfunction. There is an implausible signal.1Body
B1222External left front parking assist sensor failure22Body
B122249Temperature sensor 2 of the refrigerant compressor has a malfunction. There is an internal electrical fault.1Body
B122264Temperature sensor 2 of the refrigerant compressor has a malfunction. There is an implausible signal.1Body
B1223Internal left rear parking assist sensor failure21Body

Some brand data is extracted from diagnostic files and may contain manufacturer-specific wording. General SAE J2012 descriptions are used where available.

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