Mercedes Engine Code: Your Comprehensive Guide to Diagnostics
Mercedes-Benz vehicles are renowned for their advanced technology and intricate engineering. To ensure these vehicles operate at peak performance, their onboard computers continuously monitor a multitude of systems, sensors, and variables. When a malfunction or deviation occurs, the system generates a fault code, often referred to as a Mercedes engine code. CARDIAGTECH.NET is here to provide you with a detailed guide to understanding and diagnosing these codes. By understanding these codes, technicians and owners alike can more effectively address issues and maintain the vehicle’s optimal condition.
1. Understanding Mercedes Engine Codes
What exactly is a Mercedes engine code, and why is it important?
A Mercedes engine code, or Diagnostic Trouble Code (DTC), is a system-generated error code that identifies a malfunctioning component or system within your Mercedes-Benz. These codes are crucial because they provide a starting point for diagnosing problems, potentially saving time and resources in the repair process. According to a study by the National Institute for Automotive Service Excellence (ASE), accurate diagnosis using DTCs can reduce repair time by up to 40%.
Think of it as a digital breadcrumb dropped by your car’s computer, leading you (or your mechanic) directly to the source of the trouble. These codes can indicate a wide range of issues, from minor sensor malfunctions to significant engine or transmission problems. The Society of Automotive Engineers (SAE) has standardized DTCs, ensuring a degree of uniformity across different vehicle manufacturers, but Mercedes-Benz also has its own specific codes and nuances.
1.1 Why You Should Pay Attention to Warning Lights
Ignoring dashboard warning lights can lead to more severe and costly repairs down the road. Addressing issues promptly not only ensures the longevity of your vehicle but also maintains its safety and performance. Always take dashboard warning lights seriously and consult with a qualified technician for proper diagnosis and repair.
Dashboard lights, like the ‘Check Engine,’ ‘Brake,’ or ‘Temperature’ indicators, are your car’s way of communicating potential issues. While they might not always tell the whole story, they are a clear indication that something needs attention. A study by AAA found that 35% of drivers delay or ignore vehicle maintenance, often leading to more expensive repairs later.
1.2 Utilizing Mercedes Diagnostic Tools
Professional diagnostic tools, such as those offered by CARDIAGTECH.NET, allow technicians to accurately read and interpret Mercedes engine codes, leading to efficient and effective repairs. These tools provide valuable data, helping to pinpoint the exact cause of the problem. Equipping your garage with advanced tools can significantly improve diagnostic accuracy and reduce repair times.
These specialized tools connect to your car’s On-Board Diagnostics II (OBD-II) port and retrieve the stored fault codes. A good diagnostic tool doesn’t just read the codes; it provides detailed information about the conditions under which the code was set, freeze frame data, and even possible causes and solutions.
Alt Text: Mercedes diagnostic tool connected to OBD-II port, reading engine codes.
2. Common Mercedes Error Messages Explained
Let’s delve into some specific Mercedes engine codes, their meanings, potential causes, and the steps you can take to address them.
Understanding common Mercedes error messages can empower you to communicate effectively with your mechanic and make informed decisions about your vehicle’s maintenance. Each code provides specific insights into the system or component that is experiencing issues. According to J.D. Power, vehicles with fewer error messages reported have higher customer satisfaction ratings.
2.1 Mercedes Fault Code: P261F71
This code indicates a malfunction in the output for the circulation pump, specifically that the actuator is blocked.
| Fault Code Meaning: | The output for circulation pump has a malfunction. Actuator is blocked. |
|---|---|
| Known Problem Of: | Mercedes Sprinter Vans |
| Likely Causes: | Coolant intrusion into vacuum system via the water pump. |
| What’s Happening?: | On model OM651 4 Cylinder Diesel Engine the coolant water pump is vacuum actuated. The internal seal in the waterpump gives way and allows coolant (antifreeze) to enter the vacuum system. The vacuum system operates with the engine running. As the vehicle is driven the vacuum is so powerful it pulls coolant (antifreeeze) deeper into the vacuum system causing havoc on the entire vacuum system. |
| Possible Symptoms You May Experience | – Check Engine Light – Little to no acceleration – Coolant leak – Brake Pedal Pressure – Engine overheating |
| Parts That Could Need Replacement: | – Water Pump – Coolant – Seals – Tubes – Hoses – Vacuum Actuators – Vacuum Pump |
| System(s) Affected: | – Engine – Cooling System – Vacuum System – Turbocharging – Brake System |
| Severity: | Can be very severe if left unfixed Repair requires MASTER LEVEL Technician and not something for the DIYer |
Coolant intrusion into the vacuum system via the water pump is a common cause. On the OM651 4-cylinder diesel engine, the coolant water pump is vacuum actuated. A failing internal seal in the water pump allows coolant to enter the vacuum system. The powerful vacuum system then pulls coolant deeper, affecting various systems.
Symptoms include the check engine light, reduced acceleration, coolant leaks, brake pedal pressure issues, and engine overheating. Replacement parts may include the water pump, coolant, seals, tubes, hoses, vacuum actuators, and the vacuum pump. Affected systems include the engine, cooling system, vacuum system, turbocharging, and brake system.
Left unfixed, this issue can be severe and should be addressed by a master-level technician.
2.2 Mercedes Fault Code: P126A00 OM642 Engine Oil Cooler Leak
This code indicates that the intake port shutoff actuator is faulty.
| Fault Code Meaning: | Intake Port Shutoff Actuator is faulty. |
|---|---|
| Known Problem Of: | Mercedes Sprinter Vans |
| Likely Causes: | Failure of component: intake manifolds, or the intake manifold actuator motor. |
| What’s Happening?: | Over time (several thousand miles) 50-100k miles the inside of the intake manifolds get clogged with EGR soot, buildup causing the intake swirl flaps to stick. The sticking or binding of these flaps then binds the motor which causes the check engine light and or a sever loss of acceleration. |
| Possible Symptoms You May Experience | |
| Parts That Could Need Replacement: | |
| System(s) Affected: | – Engine |
| Severity: | Can be very severe if left unfixed Repair requires MASTER LEVEL Technician and not something for the DIYer |
The intake manifolds get clogged with EGR soot over time (50-100k miles), causing the intake swirl flaps to stick. This binding affects the motor, triggering the check engine light and a loss of acceleration.
The engine is the primarily affected system. Leaving this unfixed can be very severe and requires a master-level technician for repair.
2.3 General Fault Code Categories
Mercedes fault codes are generally categorized to help identify the affected system:
- P (Powertrain): These codes relate to the engine, transmission, and associated components.
- B (Body): These codes pertain to body-related systems like airbags, central locking, and climate control.
- C (Chassis): These codes involve chassis systems such as ABS, traction control, and suspension.
- U (Network/Communication): These codes indicate communication issues between various control modules within the vehicle.
Understanding these categories can help narrow down the source of the problem.
Alt Text: Detailed view of a Mercedes engine bay, highlighting various components.
3. Detailed Breakdown of Mercedes Fault Codes
Let’s dive deeper into specific ranges of Mercedes fault codes to give you a more comprehensive understanding.
3.1 P0400 Series Fault Codes
These codes generally relate to issues with the exhaust gas recirculation (EGR) system and related components. The EGR system is vital for reducing nitrogen oxide (NOx) emissions by recirculating a portion of the exhaust gas back into the engine’s intake. According to the EPA, a malfunctioning EGR system can significantly increase vehicle emissions and reduce fuel efficiency.
| Mercedes Fault Code | Fault Code Meaning |
|---|---|
| P0466 | Purge Flow Sensor Circuit Range/Performance |
| P0467 | Purge Flow Sensor Circuit Low Input |
| P0468 | Purge Flow Sensor Circuit High Input |
| P0469 | Purge Flow Sensor Circuit Intermittent |
| P0470 | Exhaust Pressure Sensor Malfunction |
| P0471 | Exhaust Pressure Sensor Range/Performance |
| P0472 | Exhaust Pressure Sensor Low |
| P0473 | Exhaust Pressure Sensor High |
| P0474 | Exhaust Pressure Sensor Intermittent |
| P0475 | Exhaust Pressure Control Valve Malfunction |
| P0476 | Exhaust Pressure Control Valve Range/Performance |
| P0477 | Exhaust Pressure Control Valve Low |
| P0478 | Exhaust Pressure Control Valve High |
| P0479 | Exhaust Pressure Control Valve Intermittent |
| P0480 | Cooling Fan 1 Control Circuit Malfunction |
| P0481 | Cooling Fan 2 Control Circuit Malfunction |
| P0482 | Cooling Fan 3 Control Circuit Malfunction |
| P0483 | Cooling Fan Rationality Check Malfunction |
| P0484 | Cooling Fan Circuit Over Current |
| P0485 | Cooling Fan Power/Ground Circuit Malfunction |
3.2 P0500 Series Fault Codes
The P0500 series codes often involve vehicle speed sensors, idle control systems, and other engine management components. Accurate speed readings are essential for various functions, including transmission control, ABS, and cruise control. Problems in these systems can lead to drivability issues and safety concerns.
| Mercedes Fault Code | Fault Code Meaning |
|---|---|
| P0500 | Vehicle Speed Sensor Malfunction |
| P0501 | Vehicle Speed Sensor Range/Performance |
| P0502 | Vehicle Speed Sensor Low Input |
| P0503 | Vehicle Speed Sensor Intermittent/Erratic/High |
| P0505 | Idle Control System Malfunction |
| P0506 | Idle Control System RPM Lower Than Expected |
| P0507 | Idle Control System RPM Higher Than Expected |
| P0510 | Closed Throttle Position Switch Malfunction |
| P0520 | Engine Oil Pressure Sensor/Switch Circuit Malfunction |
| P0521 | Engine Oil Pressure Sensor/Switch Circuit Range/Performance |
| P0522 | Engine Oil Pressure Sensor/Switch Circuit Low Voltage |
| P0523 | Engine Oil Pressure Sensor/Switch Circuit High Voltage |
| P0530 | A/C Refrigerant Pressure Sensor Circuit Malfunction |
| P0531 | A/C Refrigerant Pressure Sensor Circuit Range/Performance |
| P0532 | A/C Refrigerant Pressure Sensor Circuit Low Input |
| P0533 | A/C Refrigerant Pressure Sensor Circuit High Input |
| P0534 | Air Conditioner Refrigerant Charge Loss |
| P0550 | Power Steering Pressure Sensor Circuit Malfunction |
| P0551 | Power Steering Pressure Sensor Circuit Range/Performance |
| P0552 | Power Steering Pressure Sensor Circuit Low Input |
| P0553 | Power Steering Pressure Sensor Circuit High Input |
| P0554 | Power Steering Pressure Sensor Circuit Intermittent |
| P0560 | System Voltage Malfunction |
| P0561 | System Voltage Unstable |
| P0562 | System Voltage Low |
| P0563 | System Voltage High |
| P0565 | Cruise Control On Signal Malfunction |
| P0566 | Cruise Control Off Signal Malfunction |
| P0567 | Cruise Control Resume Signal Malfunction |
| P0568 | Cruise Control Set Signal Malfunction |
| P0569 | Cruise Control Coast Signal Malfunction |
| P0570 | Cruise Control Accel Signal Malfunction |
| P0571 | Cruise Control/Brake Switch A Circuit Malfunction |
| P0572 | Cruise Control/Brake Switch A Circuit Low |
| P0573 | Cruise Control/Brake Switch A Circuit High |
| P0574 | Cruise Control Related Malfunction |
| P0575 | Cruise Control Related Malfunction |
| P0576 | Cruise Control Related Malfunction |
| P0576 | Cruise Control Related Malfunction |
| P0578 | Cruise Control Related Malfunction |
| P0579 | Cruise Control Related Malfunction |
| P0580 | Cruise Control Related Malfunction |
3.3 P0600 Series Fault Codes
These codes often point to internal control module errors, generator circuit issues, or problems with the malfunction indicator lamp (MIL). These issues can affect the overall operation of the vehicle and may require specialized diagnostic equipment to resolve.
| Mercedes Fault Code | Fault Code Meaning |
|---|---|
| P0600 | Serial Communication Link Malfunction |
| P0601 | Internal Control Module Memory Check Sum Error |
| P0602 | Control Module Programming Error |
| P0603 | Internal Control Module Keep Alive Memory (KAM) Error |
| P0604 | Internal Control Module Random Access Memory (RAM) Error |
| P0605 | Internal Control Module Read Only Memory (ROM) Error |
| P0606 | PCM Processor Fault |
| P0608 | Control Module VSS Output “A” Malfunction |
| P0609 | Control Module VSS Output “B” Malfunction |
| P0620 | Generator Control Circuit Malfunction |
| P0621 | Generator Lamp “L” Control Circuit Malfunction |
| P0622 | Generator Field “F” Control Circuit Malfunction |
| P0650 | Malfunction Indicator Lamp (MIL) Control Circuit Malfunction |
| P0654 | Engine RPM Output Circuit Malfunction |
| P0655 | Engine Hot Lamp Output Control Circuit Malfunction |
| P0656 | Fuel Level Output Circuit Malfunction |
3.4 P0700 Series Fault Codes
The P0700 range of codes typically relates to the transmission control system. These codes can indicate a variety of issues, from sensor malfunctions to problems with the transmission fluid temperature or shift solenoids. Addressing transmission issues promptly is crucial to prevent further damage and maintain smooth operation.
| Mercedes Fault Code | Fault Code Meaning |
|---|---|
| P0700 | Transmission Control System Malfunction |
| P0701 | Transmission Control System Range/Performance |
| P0702 | Transmission Control System Electrical |
| P0703 | Torque Converter/Brake Switch B Circuit Malfunction |
| P0704 | Clutch Switch Input Circuit Malfunction |
| P0705 | Transmission Range Sensor Circuit malfunction (PRNDL Input) |
| P0706 | Transmission Range Sensor Circuit Range/Performance |
| P0707 | Transmission Range Sensor Circuit Low Input |
| P0708 | Transmission Range Sensor Circuit High Input |
| P0709 | Transmission Range Sensor Circuit Intermittent |
| P0710 | Transmission Fluid Temperature Sensor Circuit Malfunction |
| P0711 | Transmission Fluid Temperature Sensor Circuit Range/Performance |
| P0712 | Transmission Fluid Temperature Sensor Circuit Low Input |
| P0713 | Transmission Fluid Temperature Sensor Circuit High Input |
| P0714 | Transmission Fluid Temperature Sensor Circuit Intermittent |
| P0715 | Input/Turbine Speed Sensor Circuit Malfunction |
| P0716 | Input/Turbine Speed Sensor Circuit Range/Performance |
| P0717 | Input/Turbine Speed Sensor Circuit No Signal |
| P0718 | Input/Turbine Speed Sensor Circuit Intermittent |
| P0719 | Torque Converter/Brake Switch B Circuit Low |
| P0720 | Output Speed Sensor Circuit Malfunction |
| P0721 | Output Speed Sensor Range/Performance |
| P0722 | Output Speed Sensor No Signal |
| P0723 | Output Speed Sensor Intermittent |
| P0724 | Torque Converter/Brake Switch B Circuit High |
| P0725 | Engine Speed input Circuit Malfunction |
| P0726 | Engine Speed Input Circuit Range/Performance |
| P0727 | Engine Speed Input Circuit No Signal |
| P0728 | Engine Speed Input Circuit Intermittent |
| P0730 | Incorrect Gear Ratio |
| P0731 | Gear 1 Incorrect Ratio |
| P0732 | Gear 2 Incorrect Ratio |
| P0733 | Gear 3 Incorrect Ratio |
| P0734 | Gear 4 Incorrect Ratio |
| P0735 | Gear 5 Incorrect Ratio |
| P0736 | Reverse Incorrect Gear Ratio |
| P0740 | Torque Converter Clutch Circuit Malfuction |
| P0741 | Torque Converter Clutch Circuit Performance or Stuck Off |
| P0742 | Torque Converter Clutch Circuit Stuck On |
| P0743 | Torque Converter Clutch Circuit Electrical |
| P0744 | Torque Converter Clutch Circuit Intermittent |
| P0745 | Pressure Control Solenoid Malfunction |
| P0746 | Pressure Control Solenoid Performance or Stuck Off |
| P0747 | Pressure Control Solenoid Stuck On |
| P0748 | Pressure Control Solenoid Electrical |
| P0749 | Pressure Control Solenoid Intermittent |
| P0750 | Shift Solenoid A Malfunction |
| P0751 | Shift Solenoid A Performance or Stuck Off |
| P0752 | Shift Solenoid A Stuck On |
| P0753 | Shift Solenoid A Electrical |
| P0754 | Shift Solenoid A Intermittent |
| P0755 | Shift Solenoid B Malfunction |
| P0756 | Shift Solenoid B Performance or Stuck Off |
| P0757 | Shift Solenoid B Stuck On |
| P0758 | Shift Solenoid B Electrical |
| P0759 | Shift Solenoid B Intermittent |
| P0760 | Shift Solenoid C Malfunction |
| P0761 | Shift Solenoid C Performance or Stuck Off |
| P0762 | Shift Solenoid C Stuck On |
| P0763 | Shift Solenoid C Electrical |
| P0764 | Shift Solenoid C Intermittent |
| P0765 | Shift Solenoid D Malfunction |
| P0766 | Shift Solenoid D Performance or Stuck Off |
| P0767 | Shift Solenoid D Stuck On |
| P0768 | Shift Solenoid D Electrical |
| P0769 | Shift Solenoid D Intermittent |
| P0770 | Shift Solenoid E Malfunction |
| P0771 | Shift Solenoid E Performance or Stuck Off |
| P0772 | Shift Solenoid E Stuck On |
| P0773 | Shift Solenoid E Electrical |
| P0774 | Shift Solenoid E Intermittent |
| P0780 | Shift Malfunction |
| P0781 | 1-2 Shift Malfunction |
| P0782 | 2-3 Shift Malfunction |
| P0783 | 3-4 Shift Malfunction |
| P0784 | 4-5 Shift Malfunction |
| P0785 | Shift/Timing Solenoid Malfunction |
| P0786 | Shift/Timing Solenoid Range/Performance |
| P0787 | Shift/Timing Solenoid Low |
| P0788 | Shift/Timing Solenoid High |
| P0789 | Shift/Timing Solenoid Intermittent |
| P0790 | Normal/Performance Switch Circuit Malfunction |
3.5 P0800 Series Fault Codes
The P0800 series includes codes related to transmission and clutch control. These can range from issues with the reverse inhibit control circuit to clutch position sensor malfunctions. Proper diagnosis and repair are crucial for maintaining smooth and safe vehicle operation.
| Mercedes Fault Code | Fault Code Meaning |
|---|---|
| P0801 | Reverse Inhibit Control Circuit Malfunction |
| P0803 | 1-4 Upshift (Skip Shift) Solenoid Control Circuit Malfunction |
| P0804 | 1-4 Upshift (Skip Shift) Lamp Control Circuit Malfunction |
| P0805 | Clutch Position Sensor Circuit Malfunction |
| P0806 | Clutch Position Sensor Circuit Range/Performance |
| P0807 | Clutch Position Sensor Circuit Low |
| P0808 | Clutch Position Sensor Circuit High |
| P0809 | Clutch Position Sensor Circuit Intermittent Ckt |
| P0810 | Clutch Position Control Malfunction |
| P0811 | Clutch Slippage Excessive |
| P0812 | Reverse Input Circuit Malfunction |
| P0813 | Reverse Output Circuit Malfunction |
| P0814 | Trans Range Display Circuit Malfunction |
| P0815 | Upshift Switch Circuit Malfunction |
| P0816 | Downshift Switch Circuit Malfunction |
| P0817 | Starter Disable Circuit |
| P0818 | Driveline Disconn. Switch Input |
| P0820 | Gear Lever X-Y Sensor Circuit |
| P0821 | Gear Lever X Sensor Circuit |
| P0822 | Gear Lever Y Sensor Circuit |
| P0823 | Gear Lever X Sensor Circuit Intermittent Ckt |
| P0824 | Gear Lever Y Sensor Circuit Intermittent Ckt |
| P0830 | Clutch Position Switch A Circuit Malfunction |
| P0831 | Clutch Position Switch A Circuit Low |
| P0832 | Clutch Position Switch A Circuit High |
| P0833 | Clutch Position Switch B Circuit Malfunction |
| P0834 | Clutch Position Switch B Circuit Low |
| P0835 | Clutch Position Switch B Circuit High |
| P0836 | 4 Wheel Drive Switch Circuit Malfunction |
| P0837 | 4 Wheel Drive Switch CKT Range/Perf |
| P0838 | 4 Wheel Drive Switch Circuit Low |
| P0839 | 4 Wheel Drive Switch Circuit High |
| P0840 | Trans Fluid Press Sensor/Switch A Circuit Malfunction |
| P0841 | Trans Fluid Press Sensor/Switch A CKT Range/Perf |
| P0842 | Trans Fluid Press Sensor/Switch A Circuit Low |
| P0843 | Trans Fluid Press Sensor/Switch A Circuit High |
| P0844 | Trans Fluid Press Sensor/Switch A CKT Intermittent |
| P0845 | Trans Fluid Press Sensor/Switch B Circuit Malfunction |
| P0846 | Trans Fluid Press Sensor/Switch B CKT Range/Perf |
| P0847 | Trans Fluid Press Sensor/Switch B Circuit Low |
| P0848 | Trans Fluid Press Sensor/Switch B Circuit High |
| P0849 | Trans Fluid Press Sensor/Switch B CKT Intermittent |
3.6 P1000-P2000 Series Fault Codes
This range covers a wide array of specific issues, from electronic gear selector module defects to problems with the NOx trap efficiency. These codes often require specialized knowledge and equipment to diagnose accurately.
| Mercedes Fault Code | Fault Code Meaning |
|---|---|
| P1000 | Electronic Gear Selector Module: Defective N15/5 |
| P1228 | yet unknown code on 1997 C 220 CDI |
| P1386 | knock control |
| P1570 | Intermittant No-Start Immobiliser Module |
| P1747 | Electronic Gear Selector Module: Defective Interaction of CAN with control unit A1(instrument cluster) |
| P1750 | Electronic Gear Selector Module: Very low control unit supply voltage |
| P1832 | Electronic Gear Selector Module: SHORT in circuit N15/5 output stage |
| P1910 | Electronic Gear Selector Module: Control Unit over voltage |
| P1912 | Electronic Gear Selector Module: Weak touch push button voltage |
| P2000 | NOx Trap Efficiency Below Threshold (Bank 1) |
| P2001 | NOx Trap Efficiency Below Threshold (Bank 2) |
| P2003 | Particulate Trap Efficiency Below Threshold (Bank 1) |
| P2004 | Particulate Trap Efficiency Below Threshold (Bank 2) |
| P2031 | Exhaust Gas Temperature Sensor Circuit (Bank 1 Sensor 2) |
| P2032 | Exhaust Gas Temperature Sensor Circuit Low (Bank 1 Sensor 2) |
| P2033 | Exhaust Gas Temperature Sensor Circuit High (Bank 1 Sensor 2) |
| P2080 | Exhaust Gas Temperature Sensor Circuit Range/Performance (Bank 1 Sensor 1) |
| P2081 | Exhaust Gas Temperature Sensor Circuit intermittant (Bank 1 Sensor 1) |
| P2100 | Throttle Actuator Control Motor Circuit/Open |
| P2101 | Throttle Actuator Control Motor Circuit Range/Performance |
| P2208 | transmission: The speed of Y3/6n2 to Y3/6n3 is excessive |
Alt Text: Mercedes dashboard displaying a warning light, indicating a potential issue.
4. Body (B####) Fault Codes
These codes pertain to various body-related systems, such as lighting, air conditioning, and seat controls. Addressing these issues can improve comfort and convenience, as well as ensure the proper functioning of safety-related systems.
| Mercedes Fault Code | Fault Code Meaning |
|---|---|
| B1000 | HRA Headlamp range adjustment: Supply voltage of the control unit is too low (undervoltage) |
| B1004 | LCP Lower Control Panel: Control unit does not match vehicle type |
| B1056 | Automatic Air Conditioning: Problem in CAN communication with control unit DCM-RL |
| B1201 | Electric seat adjustment front left: Hall sensor front height M27m3 |
| B1213 | If seat memory installed: ext right rearview mirror voltage faulty |
| B1214 | If seat memory installed: ext right rearview mirror voltage faulty |
| B1226 | In-car temperature sensor (B10/4) |
| B1227 | Outside temperature indicator temp sensor (014) |
| B1128 | Heater core temperature (B10/1) |
| B1229 | Heater core temperature (B10/1) |
| B1230 | Evaporator temperature sensor (B10/6) |
| B1231 | ECT sensor (B11/4) |
| B1232 | Refrigerant pressure sensor (B12) |
| B1233 | Refrigerant temperature sensor (B12/1) |
| B1234 | Sun sensor (B32) |
| B1235 | Emissions sensor (B31) |
| B1241 | Refrigerant Fill |
| B1246 | PTS Parktronic: A42b1 (left outer sensor, front bumper) The plug connection has poor contact or is loose, or the sensor or cable is faulty |
| B1310 | Left/Window airbag sensor is defective |
| B1315 | Problem in Front passenger child seat recognition |
| B1416 | Coolant circulation pump (M13) |
| B1417 | Duovalve (Y21y1), left |
| B1418 | Duovalve (Y21y2), right |
| B1419 | Electromagnetic clutch (A9k1) |
| B1420 | Idle speed increase |
| B1421 | Pulse module (N05) |
| B1422 | Series interface (K1) connection to instrument cluster (A1) |
| B1423 | Switchover valve block (Y11) |
| B1424 | Activated charcoal filler actuator (A32m2) open |
| B1425 | Activated charcoal filler actuator (A32m2) closed |
| B1432 | Non-USA DTC |
| B1459 | Series interface (K2) connection to instrument cluster (A1) |
| B1462 | Wide open throttle (WOT) position signal diesel engines |
| B1476 | Airbag malfunction indicator and warning lamp is defective |
| B1481 | HRA: Part E2m1 (Right headlamp range adjustment motor) has short to ground |
| B1489 | HRA: Part E2m1 (Right headlamp range adjustment motor) has open or short to positive |
| B1492 | HRA: Part E1m1 (Left headlamp range adjustement motor) has short to positive/td> |
| B1617 | Part E19/1 (Left license plate lamp) is defective |
| B1618 | Part E19/2 (Right license plate lamp) is defective |
| B1628 | Part E2e5 (Turn signal lamp) in module E2 (Right front headlamp unit) is defective. |
| B1703 | Intermittant No Start in AAM Immobiliser Module |
| B1729 | PSE Pneumatic system doorlock Control Module A37 |
| B1736 | Navigation system’s CD Player: Check General CD, Check CD data block, Flimsy CD data |
| B1768 | Faulty open data flap limit switch (0025) Front flap |
| B1773 | HRA: Zero position programming has not yet been carried out or is not possible |
| B1850 | Electric seat adjustment front right: CAN communication interrupted with DCMC1000 Traction System Control Module |
5. Chassis (C####) Fault Codes
C-level fault codes relate to chassis components like the ABS, ESP, and AIRmatic suspension. These systems are essential for safety and ride comfort, so addressing these codes quickly is very important.
| Mercedes Fault Code | Fault Code Meaning |
|---|---|
| C1010 | Battery Voltage Low |
| C1011 | ASR/ETS/ESP Circuit Open or Shorted |
| C1012 | Battery Voltage High |
| C1020 | CAN Communication Fault |
| C1021 | CAN Communication With EA/CC/ISC Control Module Interrupted |
| C1024 | CAN Communication With Engine Control Module Interrupted |
| C1025 | CAN Communication BAS communication with ESP control unit faulty |
| C1100 | Left Front Axle VSS Circuit Fault |
| C1101 | Right Front Axle VSS Circuit Fault |
| C1102 | ETS/ASR, ABS Left Axle VSS Circuit Fault |
| C1103 | Right Rear Axle VSS Circuit Fault |
| C1121 | AIRmatic: fault in component B22/3 (level sensor) |
| C1122 | AIRmatic: fault in component B22/4 (level sensor) |
| C1123 | AIRmatic: fault in component B22/6 (level sensor) |
| C1132 | AIRmatic: fault in component B22/8 (level sensor) |
| C1133 | AIRmatic: fault in component B22/9 (level sensor) |
| C1135 | AIRmatic: fault in component B22/3 (level sensor) |
| C1140 | BAS light, play in steering column causes steering angle sensor to lose memory(?) |
| C1142 | ABS Lateral Acceleration Sensor Open/Shorted |
| C1144 | AIRmatic: fault in component B7 (pressure sensor) |
| C1200 | Stop Light Switch Open/Shorted/Implausible |
| C1300 | Left Front Axle Solenoid Valve (Hold) (A7/3y6) Open/Shorted |
| C1303 | Right Front Axle Solenoid Valve (Hold) Open/Shorted |
| C1311 | Switchover Solenoid Valve (Release) Open/Shorted |
| C1312 | Master Cylinder Switchover Valve |
| C1401 | High Pressure Return Pump Circuit Open/Shorted; Will Not Shut Off |
| C1501 | SPS P-Valve |
| C1504 | BAS light, play in steering column causes steering angle sensor to lose memory(?) |
| C1512 | Brakes Overheated |
| C1600 | Temperature After Engine Is Turned OffU0001 High Speed CAN Communication Bus |
6. U0 Codes: Network Communication
U0 codes involve communication issues between different control modules. A malfunctioning communication network can lead to various problems. Quick diagnosis and repair are essential to maintain vehicle operation.
| Mercedes Fault Code | Fault Code Meaning |
|---|---|
| U0002 | High Speed CAN Communication Bus Performance |
| U0003 | High Speed CAN Communication Bus (+) open |
| U0004 | High Speed CAN Communication Bus (+) low |
| U0005 | High Speed CAN Communication Bus (+) high |
| U0006 | High Speed CAN Communication Bus (-) open |
| U0007 | High Speed CAN Communication Bus (-) low |
| U0008 | High Speed CAN Communication Bus (-) high |
| U0009 | High Speed CAN Communication Bus (-) shorted to Bus (+) |
| U0010 | Medium Speed CAN Communication Bus |
| U0011 | Medium Speed CAN Communication Bus Performance |
| U0012 | Medium Speed CAN Communication Bus (+) open |
| U0013 | Medium Speed CAN Communication Bus (+) low |
| U0014 | Medium Speed CAN Communication Bus (+) high |
| U0015 | Medium Speed CAN Communication Bus (-) open |
| U0016 | Medium Speed CAN Communication Bus (-) low |
| U0017 | Medium Speed CAN Communication Bus (-) high |
| U0018 | Medium Speed CAN Communication Bus (-) shorted to Bus (+) |
| U0019 | Low Speed CAN Communication Bus |
| U0020 | Low Speed CAN Communication Bus Performance |
| U0021 | Low Speed CAN Communication Bus (+) open |
| U0022 | Low Speed CAN Communication Bus (+) low |
| U0023 | Low Speed CAN Communication Bus (+) high |
| U0024 | Low Speed CAN Communication Bus (-) open |
| U0025 | Low Speed CAN Communication Bus (-) low |
| U0026 | Low Speed CAN Communication Bus (-) high |
| U0027 | Low Speed CAN Communication Bus (-) shorted to Bus (+) |
| U0028 | Vehicle Communication Bus A |
