Mercedes Engine Fault Codes: Your Ultimate Diagnostic Guide
Mercedes Engine Fault Codes can be a source of confusion and frustration. This comprehensive guide, brought to you by CARDIAGTECH.NET, is designed to help you understand these codes, diagnose potential issues, and keep your Mercedes running smoothly. With the right tools and knowledge, you can address these problems efficiently and maintain the performance of your vehicle.
1. Understanding Mercedes Engine Fault Codes
What are Mercedes Engine Fault Codes and why are they important?
Mercedes-Benz fault codes, also known as Diagnostic Trouble Codes (DTCs), are codes generated by your vehicle’s onboard computer system when it detects a malfunction. These codes are essential for diagnosing issues in various systems, helping technicians pinpoint problems accurately. According to a study by the University of California, Berkeley, using diagnostic tools can reduce repair time by up to 40%, making them indispensable for modern automotive repair.
1.1. The Role of Onboard Diagnostics
How do onboard diagnostics help in identifying problems?
Modern Mercedes vehicles are equipped with sophisticated onboard diagnostic systems that monitor hundreds of sensors and systems. When a deviation or error is detected, the system generates a specific fault code. This code provides a starting point for technicians to investigate the problem, leading to faster and more accurate repairs.
1.2. Decoding Fault Codes
What does each part of a fault code signify?
Mercedes fault codes typically follow a standardized format. For example, a code like P0300 indicates a misfire in multiple cylinders. The “P” signifies a powertrain code, “0” is a generic code, “3” indicates the misfire subcategory, and “00” specifies multiple cylinders. Understanding this structure helps in narrowing down the potential issues.
1.3. Common Triggers for Fault Codes
What are the typical issues that trigger fault codes in Mercedes engines?
Fault codes can be triggered by a wide range of issues, including:
- Sensor malfunctions
- Electrical problems
- Mechanical failures
- Software glitches
According to the National Institute for Automotive Service Excellence (ASE), sensor malfunctions account for approximately 60% of all fault codes in modern vehicles.
2. Essential Tools for Diagnosing Mercedes Fault Codes
What tools are needed to diagnose and address Mercedes engine fault codes effectively?
Diagnosing Mercedes fault codes requires the right tools. Here are some essential items available at CARDIAGTECH.NET:
- OBD-II Scanner: Reads and clears fault codes.
- Multimeter: Tests electrical components.
- Diagnostic Software: Provides detailed information about fault codes.
- Specialized Sockets and Wrenches: For Mercedes-specific components.
- Smoke Machine: Detects vacuum leaks.
2.1. The Importance of an OBD-II Scanner
Why is an OBD-II scanner a must-have for Mercedes owners and technicians?
An OBD-II (On-Board Diagnostics II) scanner is crucial for reading and interpreting fault codes. It connects to your Mercedes’ diagnostic port, allowing you to retrieve stored codes and clear them after repairs. Modern scanners also provide live data, freeze-frame data, and advanced diagnostic functions.
2.2. Diagnostic Software
How does specialized diagnostic software enhance the fault code reading process?
Specialized diagnostic software, like those compatible with Mercedes-Benz, offers in-depth information about fault codes. These programs often include:
- Detailed code descriptions
- Possible causes
- Troubleshooting steps
- Wiring diagrams
This level of detail can significantly speed up the diagnostic process.
2.3. Multimeters for Electrical Testing
When is a multimeter necessary for diagnosing Mercedes engine issues?
A multimeter is essential for testing electrical components and circuits. It can measure voltage, current, and resistance, helping you identify issues such as:
- Short circuits
- Open circuits
- Faulty sensors
- Wiring problems
2.4. Specialized Tools
What Mercedes-specific tools can simplify the repair process?
Mercedes-Benz vehicles often require specialized tools due to their unique designs. These tools can include:
- Socket sets for specific bolt sizes
- Wrenches for unique fittings
- Tools for removing interior panels without damage
Using the right tools ensures efficient and safe repairs.
3. Common Mercedes Engine Fault Codes and Their Meanings
What are some frequent Mercedes engine fault codes and what do they indicate?
Here’s a detailed look at some common Mercedes engine fault codes:
3.1. P0400 Series: Exhaust Gas Recirculation (EGR) Issues
What do P0400 series codes indicate and how do you address them?
The P0400 series of codes relates to the Exhaust Gas Recirculation (EGR) system. The EGR system reduces emissions by recirculating a portion of the exhaust gas back into the engine’s intake. Common codes in this series include:
| 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 |
Common causes:
- Faulty EGR valve
- Clogged EGR passages
- Defective EGR sensor
- Vacuum leaks in the EGR system
Troubleshooting steps:
- Inspect the EGR valve for carbon buildup and proper operation.
- Check EGR passages for blockages.
- Test the EGR sensor with a multimeter.
- Look for vacuum leaks in the EGR system using a smoke machine.
3.2. P0500 Series: Vehicle Speed Sensor (VSS) Issues
What do P0500 series codes indicate and how do you resolve them?
The P0500 series of codes relates to the Vehicle Speed Sensor (VSS). The VSS provides the vehicle’s speed information to the engine control unit (ECU), transmission control unit (TCU), and other systems. Common codes in this series include:
| 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 |
Common causes:
- Faulty VSS sensor
- Wiring issues
- Damaged or corroded connectors
- Problems with the ABS system
Troubleshooting steps:
- Inspect the VSS sensor for damage.
- Check the wiring and connectors for corrosion or damage.
- Test the VSS sensor with a multimeter.
- Examine the ABS system for related issues.
3.3. P0600 Series: Internal Control Module Issues
What do P0600 series codes mean and how should they be addressed?
The P0600 series of codes indicates problems with the internal control module, which can be a serious issue. These codes suggest that there is a malfunction within the ECU or other control modules. Common codes in this series include:
| 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 |
Common causes:
- Faulty ECU
- Software corruption
- Wiring issues
- Poor connections
Troubleshooting steps:
- Check the ECU for physical damage.
- Inspect wiring and connections for issues.
- Attempt to reprogram the ECU with updated software.
- If the problem persists, the ECU may need replacement.
3.4. P0700 Series: Transmission Control System Malfunctions
What do P0700 series codes signify and how do you handle them?
The P0700 series of codes relates to the transmission control system. These codes indicate issues with the transmission’s operation, which can affect shifting and overall performance. Common codes in this series include:
| 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 |
Common causes:
- Low transmission fluid
- Faulty shift solenoids
- Damaged wiring
- Internal transmission issues
Troubleshooting steps:
- Check the transmission fluid level and condition.
- Inspect shift solenoids for proper function.
- Examine wiring and connections for damage.
- Consider internal transmission issues if external checks are normal.
3.5. P0800 Series: Transmission-Related Control Circuit Issues
What do P0800 series codes indicate and how can they be resolved?
The P0800 series of codes pertains to transmission-related control circuit malfunctions. These codes often involve issues with the clutch, switches, and other control mechanisms. Common codes in this series include:
| 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 |
Common causes:
- Faulty switches
- Wiring problems
- Sensor malfunctions
- Clutch issues
Troubleshooting steps:
- Inspect switches and sensors for proper operation.
- Check wiring and connections for damage.
- Test sensors with a multimeter.
- Address clutch issues if present.
3.6. P1000-P2000 Series: Manufacturer-Specific Codes
What do P1000-P2000 series codes signify and how should they be approached?
The P1000-P2000 series of codes are manufacturer-specific, meaning they are unique to Mercedes-Benz. These codes can cover a wide range of issues, from transmission problems to fuel system malfunctions. Common codes in this series include:
| 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 |
Common causes:
- Vary widely depending on the specific code
- Require detailed diagnostic information
Troubleshooting steps:
- Use Mercedes-specific diagnostic software for detailed code information.
- Consult the Mercedes-Benz service manual for troubleshooting steps.
- Check related components and systems based on the code description.
4. Mercedes Body Fault Codes (B-Codes)
What are Mercedes body fault codes (B-codes) and what systems do they cover?
Mercedes body fault codes, also known as B-codes, pertain to issues within the vehicle’s body systems, such as airbags, central locking, and climate control. These codes are essential for diagnosing problems that affect comfort, convenience, and safety. Common codes in this series include:
| 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 |
Common causes:
- Electrical faults
- Sensor issues
- Module malfunctions
- Communication problems
Troubleshooting steps:
- Use a diagnostic scanner to read the specific B-code.
- Check wiring and connectors related to the affected system.
- Test sensors and components with a multimeter.
- Consult the Mercedes-Benz service manual for detailed troubleshooting.
5. Mercedes Chassis Fault Codes (C-Codes)
What are Mercedes chassis fault codes (C-codes) and which systems do they cover?
Mercedes chassis fault codes, identified as C-codes, relate to issues within the vehicle’s chassis systems, including ABS, ESP, and AIRMATIC suspension. These codes are crucial for diagnosing problems that affect handling, stability, and ride comfort. Common codes in this series include:
| 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 |
