Mercedes-Benz Engine Fault Codes: Your Comprehensive Guide
Mercedes-Benz engine fault codes are diagnostic trouble codes (DTCs) that indicate a malfunction in your vehicle’s engine or related systems. With the sophisticated engineering of Mercedes-Benz vehicles, CARDIAGTECH.NET provides the expertise to decode these codes and guide you toward effective solutions. Understanding these codes, their potential causes, and the necessary repairs is crucial for maintaining your Mercedes-Benz’s performance and longevity.
1. Understanding Mercedes-Benz Engine Fault Codes
Fault codes in Mercedes-Benz vehicles are essentially error messages generated by the car’s onboard computer, signaling that something is not functioning as expected. These codes are critical for diagnosing and addressing issues, ensuring your vehicle runs smoothly.
1.1. What is a Fault Code?
A fault code, also known as a Diagnostic Trouble Code (DTC), is a system code error that alerts you to a malfunction in your Mercedes-Benz. Modern Mercedes models will display a warning light or error message on the dashboard when a fault code is triggered, prompting you to seek inspection.
1.1.1. The Role of Onboard Computers
Mercedes-Benz vehicles are equipped with onboard computers that monitor hundreds of systems, sensors, and variables. These computers make real-time adjustments to optimize performance, shifting, braking, traction, stability, and safety. When a deviation or error occurs, the computer registers a fault code.
1.1.2. Identifying Fault Codes
Fault codes trigger dashboard lights, such as “Check Engine,” “Brake,” or “Temperature.” However, these lights often don’t provide enough information for a precise diagnosis. Consulting a specialist or using a diagnostic tool is essential for accurate identification.
1.2. Why are Fault Codes Important?
Understanding and addressing fault codes is essential for maintaining the health and performance of your Mercedes-Benz. Neglecting these codes can lead to more significant and costly issues down the line.
1.2.1. Early Detection of Problems
Fault codes enable early detection of issues, allowing you to address them before they escalate into major problems. For instance, a fault code related to the cooling system can prevent engine overheating, which can cause severe damage.
1.2.2. Maintaining Performance
Addressing fault codes promptly helps maintain your vehicle’s optimal performance. For example, resolving a fault code related to the fuel injection system can improve fuel efficiency and engine power.
1.2.3. Ensuring Longevity
Regularly checking and addressing fault codes can extend the lifespan of your Mercedes-Benz. By fixing minor issues early, you can prevent wear and tear on critical components, ensuring your vehicle remains reliable for years to come.
1.3. Common Mercedes Error Messages
Some common error messages in Mercedes-Benz vehicles include:
- Check Engine Light: Indicates a problem with the engine or related systems.
- Brake Light: Signals an issue with the braking system.
- Temperature Warning: Indicates that the engine is overheating.
- ABS Warning: Indicates a problem with the Anti-lock Braking System.
- SRS Warning: Signals an issue with the Supplemental Restraint System (airbags).
1.4. Tools for Reading Fault Codes
To read Mercedes-Benz fault codes accurately, you’ll need specific diagnostic tools. These tools connect to your vehicle’s OBD-II port and provide detailed information about the detected issues.
1.4.1. OBD-II Scanners
OBD-II (On-Board Diagnostics II) scanners are essential tools for reading fault codes. These scanners plug into your vehicle’s OBD-II port, typically located under the dashboard, and retrieve diagnostic information.
1.4.1.1. Basic OBD-II Scanners
Basic scanners are affordable and provide essential information, such as fault codes and their descriptions. They are suitable for simple diagnostics and clearing codes.
1.4.1.2. Advanced OBD-II Scanners
Advanced scanners offer more features, such as live data streaming, component testing, and bidirectional control. These are ideal for professional technicians and serious DIYers.
According to a study by the National Institute for Automotive Service Excellence (ASE), using advanced diagnostic tools can reduce diagnostic time by up to 40%.
1.4.2. Mercedes-Specific Diagnostic Tools
For more in-depth diagnostics, consider using Mercedes-specific diagnostic tools, such as the Mercedes-Benz Star Diagnosis system. These tools provide comprehensive access to your vehicle’s systems and offer advanced functionalities.
1.4.2.1. Mercedes-Benz Star Diagnosis
The Star Diagnosis system is the official diagnostic tool used by Mercedes-Benz dealerships and certified repair shops. It offers unparalleled access to your vehicle’s systems, including engine, transmission, ABS, SRS, and more.
1.4.2.2. iCarsoft MB II
The iCarsoft MB II is a popular aftermarket diagnostic tool specifically designed for Mercedes-Benz vehicles. It offers many of the same features as the Star Diagnosis system but at a more affordable price.
1.4.3. Smartphone Apps and Adapters
Another option is to use smartphone apps and adapters that connect to your vehicle’s OBD-II port via Bluetooth or Wi-Fi. These apps can read fault codes and provide real-time data on your smartphone or tablet.
1.4.3.1. Torque Pro
Torque Pro is a popular Android app that connects to your vehicle via an OBD-II adapter. It offers a wide range of features, including fault code reading, live data monitoring, and performance testing.
1.4.3.2. OBD Fusion
OBD Fusion is a versatile app available for both iOS and Android devices. It supports a variety of OBD-II adapters and offers comprehensive diagnostic capabilities.
Using these tools can save you time and money by enabling you to diagnose and address issues yourself or provide accurate information to your mechanic.
2. Common Mercedes-Benz Fault Codes Explained
Understanding the meaning behind Mercedes-Benz fault codes is crucial for effective diagnostics and repairs. Here are some common fault codes and their explanations:
2.1. P261F71: Circulation Pump Malfunction
| 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 |
This fault code indicates a malfunction in the circulation pump, often found in Mercedes Sprinter Vans. According to a study by Daimler, coolant intrusion into the vacuum system via a faulty water pump is a common cause.
2.1.1. Symptoms
Common symptoms include:
- Check Engine Light
- Reduced acceleration
- Coolant leak
- Brake pedal pressure issues
- Engine overheating
2.1.2. Possible Solutions
Possible solutions include replacing the water pump, coolant, seals, tubes, hoses, vacuum actuators, and vacuum pump.
2.2. P126A00: OM642 Engine Oil Cooler Leak
| 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 | Check Engine Light, loss of acceleration |
| Parts That Could Need Replacement: | Intake manifolds, or the intake manifold actuator motor. |
| System(s) Affected: | Engine |
| Severity: | Can be very severe if left unfixed Repair requires MASTER LEVEL Technician and not something for the DIYer |
This code indicates a faulty intake port shutoff actuator, often due to clogged intake manifolds. Research from Mercedes-Benz suggests that EGR soot buildup over time causes the intake swirl flaps to stick.
2.2.1. Symptoms
Common symptoms include:
- Check Engine Light
- Loss of acceleration
2.2.2. Possible Solutions
Possible solutions include replacing the intake manifolds or the intake manifold actuator motor.
2.3. P0400 Series: Exhaust Gas Recirculation (EGR) Issues
The P0400 series of fault codes relate to the Exhaust Gas Recirculation (EGR) system. The EGR system helps reduce emissions by recirculating a portion of the exhaust gas back into the engine.
| 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 |
2.3.1. Common Causes
Common causes include:
- Faulty EGR valve
- Clogged EGR passages
- Defective EGR sensor
- Vacuum leaks
2.3.2. Possible Solutions
Possible solutions include:
- Cleaning or replacing the EGR valve
- Clearing clogged EGR passages
- Replacing the EGR sensor
- Repairing vacuum leaks
2.4. P0500 Series: Vehicle Speed Sensor (VSS) Issues
The P0500 series of fault codes relate to the Vehicle Speed Sensor (VSS), which measures the speed of the vehicle and sends this information to the engine control unit (ECU).
| 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 |
2.4.1. Common Causes
Common causes include:
- Faulty VSS
- Wiring issues
- Connector problems
- ECU malfunction
2.4.2. Possible Solutions
Possible solutions include:
- Replacing the VSS
- Repairing or replacing damaged wiring
- Cleaning or replacing connectors
- Replacing or reprogramming the ECU
2.5. P0600 Series: Internal Control Module Issues
The P0600 series of fault codes relate to internal control module issues, indicating a problem with the vehicle’s computer systems.
| 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 |
2.5.1. Common Causes
Common causes include:
- Software errors
- Hardware failures
- Communication issues
- Voltage problems
2.5.2. Possible Solutions
Possible solutions include:
- Reprogramming the control module
- Replacing the control module
- Repairing wiring and connections
- Addressing voltage issues
2.6. P0700 Series: Transmission Control System Issues
The P0700 series of fault codes relate to the transmission control system, indicating problems with the transmission’s 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 |
2.6.1. Common Causes
Common causes include:
- Low transmission fluid
- Faulty shift solenoids
- Defective transmission sensors
- Worn transmission components
2.6.2. Possible Solutions
Possible solutions include:
- Checking and refilling transmission fluid
- Replacing shift solenoids
- Replacing transmission sensors
- Repairing or replacing the transmission
2.7. P0800 Series: Transmission Related Issues
The P0800 series of fault codes relate to various transmission-related issues, often involving switches and circuits.
| 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 |
2.7.1. Common Causes
Common causes include:
- Faulty switches
- Wiring issues
- Sensor malfunctions
- Control module problems
2.7.2. Possible Solutions
Possible solutions include:
- Replacing faulty switches
- Repairing or replacing wiring
- Replacing sensors
- Addressing control module issues
2.8. P1000-P2000 Series: Various Engine and Transmission Issues
The P1000-P2000 series includes a wide range of fault codes related to engine and transmission issues.
| 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 |
2.8.1. Common Causes
Common causes vary widely depending on the specific code, including:
- Sensor failures
- Actuator malfunctions
- Electrical issues
- Module defects
2.8.2. Possible Solutions
Possible solutions vary depending on the specific code, including:
- Replacing sensors
- Replacing actuators
- Repairing wiring
- Replacing or reprogramming modules
2.9. B-Level Codes: Body Control System Issues
B-level codes relate to the body control system, which manages various functions such as lighting, door locks, and climate control.
| 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 |
2.9.1. Common Causes
Common causes include:
- Sensor failures
- Wiring issues
- Module malfunctions
2.9.2. Possible Solutions
Possible solutions include:
- Replacing sensors
- Repairing wiring
- Replacing or reprogramming modules
2.10. C-Level Codes: Chassis Control System Issues
C-level codes relate to the chassis control system, which manages functions such as ABS, traction control, and stability control.
| 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) |
| C1 |
