Mercedes-Benz engine control units – tested replacement ECUs
A Mercedes-Benz engine control unit, also known as an ECU, ECM or engine computer, controls essential engine functions such as fuel injection, ignition, turbocharger operation, EGR, DPF regeneration and communication with other electronic modules.
ECUSale supplies original, tested Mercedes-Benz engine controllers for diesel and petrol vehicles. The range includes modules for selected A-Class, B-Class, C-Class, E-Class, S-Class, CLK, CLS, SL, SLK, ML, GL, GLC, Vito, Viano and Sprinter models. Availability depends on the complete OEM number, ECU manufacturer, engine version, hardware and installed software.
Need help identifying your Mercedes-Benz ECU?
Send a photograph showing the entire label of your original controller and provide the vehicle’s VIN. We will compare the Mercedes-Benz and manufacturer numbers and help you select the appropriate module.
Ask us to check compatibility
Mercedes-Benz 2.2 CDI ECU controllers
A significant part of our range consists of Bosch engine controllers for Mercedes-Benz vehicles equipped with 2.2 CDI diesel engines. These modules were installed in numerous passenger cars and vans, including selected Sprinter, Vito and Viano versions.
One example is the A6461500577 / Bosch 0281014203 Mercedes 2.2 CDI CR4.20 VIRGIN ECU. It is supplied reset and prepared for personalisation using Mercedes Star Diagnosis or Xentry.
Another available version is the A6461507272 / Bosch 0281015062 Mercedes 2.2 CDI OM646 VIRGIN ECU. The OM646 engine designation alone does not confirm compatibility. Both the Mercedes-Benz OEM number and the complete Bosch number should be compared with the original controller.
Different CR4.20 and CR4.21 controllers can have similar housings and connectors while containing different hardware or software. They should not be selected solely according to engine capacity, vehicle model or production year.
Mercedes-Benz 3.0 CDI OM642 ECU
The Mercedes-Benz OM642 3.0 CDI engine was used in many passenger cars, SUVs and vans. Several ECU variants were fitted depending on the model, emissions standard, power output, gearbox and production period.
The range includes the A6429002900 / Bosch 0281016383 Mercedes 3.0 CDI OM642 CR6P.15 VIRGIN ECU. The controller has been reset, but it must still be correctly personalised, programmed and coded after installation.
When selecting an OM642 controller, check the complete Mercedes-Benz A-number, Bosch number, ECU family, hardware and software version. “Mercedes 3.0 CDI ECU” is not a sufficiently precise part description.
Looking for a Mercedes-Benz CDI ECU?
Compare every number on the original label. Two ECUs designed for the same engine family may contain different hardware, software or vehicle configurations.
View Mercedes-Benz ECUs Check your part numbers
Mercedes-Benz petrol engine ECUs
ECUSale also offers Bosch controllers for selected Mercedes-Benz petrol engines, including V6 units from the M112, M272 and M276 families.
Mercedes-Benz ME9.7 ECU for M272 engines
The A2721533291 / Bosch 0261209220 Mercedes-Benz ME9.7 VIRGIN engine control unit is intended for selected vehicles equipped with an M272 petrol engine. Compatibility must be established from the complete numbers and the vehicle configuration.
Mercedes-Benz M276 3.5 V6 ECU
Available M276 controllers include the A2769001600 / Bosch 0261S06497 Mercedes 3.5 V6 M276 VIRGIN ECU and the A2769005000 / Bosch 0261S07801 Mercedes W204 3.5 V6 VIRGIN ECU.
Although both controllers may be associated with a 3.5-litre M276 engine, they are not automatically interchangeable. The complete OEM and Bosch references, hardware, software, model generation and equipment configuration must be verified.
Mercedes-Benz B-Class B200 CDI ECU
For selected Mercedes-Benz B-Class W245 vehicles, the range includes the A6409003700 / Bosch 0281017236 Mercedes B200 CDI W245 VIRGIN ECU.
Before ordering, confirm that both numbers match the original controller. The B200 CDI model designation alone does not identify the exact engine computer because different controllers may have been fitted during the model’s production.
How to choose the correct Mercedes-Benz engine ECU
The most reliable identification method is to compare all numbers printed on the original ECU label. The vehicle model, engine capacity, power output and production year are helpful, but they are not sufficient on their own.
Before purchasing, check:
- the complete Mercedes-Benz OEM number beginning with the letter A,
- the complete Bosch, Continental, Siemens, VDO, Delphi or other manufacturer number,
- the ECU family, such as CR4.20, CR4.21, CR6P or ME9.7,
- the hardware and software versions,
- the engine code and power output,
- the emissions standard,
- the gearbox type and vehicle equipment,
- the model series and generation.
The VIN helps identify the vehicle but does not replace the numbers printed on the original module. For example, a Mercedes-Benz number such as A6461507272 should be checked together with Bosch number 0281015062.
Mercedes-Benz VIRGIN ECU – what does it mean?
A VIRGIN Mercedes-Benz ECU has been reset and cleared of the relevant assignment data from the previous vehicle. This allows a compatible controller to be personalised and integrated with another vehicle.
VIRGIN does not mean that the ECU will operate immediately after being connected. Depending on the model and controller type, installation may require:
- initial commissioning of the replacement ECU,
- personalisation to the vehicle,
- synchronisation with the drive authorisation system,
- VIN entry,
- installation of the correct software,
- variant coding,
- SCN coding where required,
- clearing faults and testing communication with related modules.
These procedures should be performed by an experienced Mercedes-Benz specialist using Star Diagnosis or Xentry and a stable external power supply.
Mercedes-Benz drive authorisation and ECU programming
The engine ECU communicates with the vehicle’s drive authorisation components. Depending on the model, these may include the key, EIS/EZS ignition module, transmission controller, ISM selector module and other control units.
Incorrect personalisation, missing coding, low voltage during programming or a communication fault in another module may prevent the engine from starting even when the replacement ECU itself is working correctly.
ECUSale does not offer Mercedes-Benz engine controllers with IMMO OFF. The correct replacement methods for the controllers in this category are VIRGIN preparation followed by authorised personalisation and coding, or cloning when technically possible.
Mercedes-Benz ECU cloning
Cloning involves transferring the required memory and configuration data from the original ECU to a compatible replacement controller. Depending on the ECU type, this can include EEPROM, FLASH, processor data, VIN, software, configuration and drive authorisation information.
Cloning may reduce the amount of work required after installation, but it is only possible when:
- the original controller can still be read correctly,
- the replacement ECU is technically compatible,
- the transferred software and configuration are suitable for the vehicle.
If the original module is severely damaged or its data cannot be recovered, a correctly selected VIRGIN controller followed by programming with Xentry or Star Diagnosis is usually the appropriate solution.
Engine ECU, transmission controller and Mercedes-Benz ISM faults
The engine controller exchanges data with the automatic transmission ECU, EGS/TCM and, in selected models, the Intelligent Servo Module. A vehicle that remains in P, does not recognise the selected gear, returns to N or records CAN communication faults does not necessarily have a defective engine ECU.
When replacing an ISM or transmission module, the required procedure may include calibration of the selector, programming or adaptation of the transmission controller, fault clearing and a complete communication test. More information is available in our guide to Mercedes A1644460710 ISM failure, VIRGIN preparation and cloning.
Common symptoms of a faulty Mercedes-Benz ECU
- the engine does not start or starts intermittently,
- no diagnostic communication with the engine ECU,
- the engine stalls while driving or after warming up,
- limp mode and reduced engine power,
- injector, ignition or fuel pressure faults,
- turbocharger or emissions-system control faults,
- drive authorisation or immobiliser-related errors,
- CAN communication errors involving EIS/EZS, ISM or the transmission controller,
- failure following interrupted ECU programming,
- damage caused by water, a short circuit, reverse polarity or overvoltage.
These symptoms can also be caused by damaged wiring, poor grounds, missing power supplies, faulty relays, sensors, injectors or other electronic modules. A complete vehicle diagnosis should be carried out before ordering a replacement engine ECU.
What should be checked before replacing the ECU?
- ECU power supplies and ground connections,
- fuses and relays,
- wiring harnesses and connectors,
- CAN network communication,
- key recognition and drive authorisation status,
- EIS/EZS and related modules,
- battery condition and alternator charging voltage,
- injectors, actuators and sensors that could be causing a short circuit.
A replacement controller should not be installed before the original cause of electrical damage has been identified. A short circuit or charging-system fault can damage the replacement ECU as well.
Other Mercedes-Benz electronic modules
Engine starting and vehicle operation depend on communication between several electronic systems. In addition to engine ECUs, ECUSale offers Mercedes-Benz ABS pumps and brake control modules.
If the vehicle has braking-system warnings, wheel-speed sensor faults, no communication with the ABS controller or recurring CAN errors, diagnose the ABS/ESP system separately rather than assuming that the engine ECU is responsible.
Why buy a Mercedes-Benz ECU from ECUSale?
- original Bosch, Continental, Siemens, VDO, Delphi and other modules,
- controllers tested before dispatch,
- clear Mercedes-Benz OEM and manufacturer numbers,
- information about VIRGIN condition and programming requirements,
- compatibility assistance based on the original label and VIN,
- warranty in accordance with the terms stated for the product,
- national and international delivery.
Before ordering, you can review our purchasing information, available payment methods, delivery times and shipping costs and returns and complaints policy.
Find the correct Mercedes-Benz engine ECU
Compare every number on your original controller or send us a photograph of its complete label. We will help you identify a compatible ECU and the appropriate preparation method.
View Mercedes-Benz ECUs Request a compatibility check
FAQ – Mercedes-Benz engine control units
Does a Mercedes-Benz engine ECU need identical numbers?
The safest option is an ECU with the same complete Mercedes-Benz OEM number and a matching manufacturer number. Some modules have recognised replacement numbers, but compatibility must be confirmed before purchase.
Will a Mercedes-Benz VIRGIN ECU work immediately after installation?
No. A VIRGIN ECU normally requires personalisation, drive authorisation synchronisation, suitable software and coding using Mercedes Star Diagnosis or Xentry before the vehicle can be started and operated correctly.
How is a VIRGIN Mercedes-Benz ECU programmed?
The exact procedure depends on the ECU and vehicle generation. It may include initial commissioning, VIN entry, personalisation, software flashing, variant coding and SCN coding. The work should be carried out by a Mercedes-Benz specialist using Xentry or Star Diagnosis.
Does ECUSale offer Mercedes-Benz engine ECUs with IMMO OFF?
No. We do not offer IMMO OFF for Mercedes-Benz engine controllers. We supply compatible modules prepared as VIRGIN for correct personalisation and programming, or offer cloning when the original ECU data can be recovered.
Can a Mercedes-Benz ECU be cloned?
Cloning may be possible if the original controller remains readable and the replacement module is compatible. The original ECU may need to be sent for inspection and data transfer.
Is the VIN enough to identify a Mercedes-Benz ECU?
The VIN is useful for identifying the vehicle, but it does not replace the part numbers on the controller. Send the VIN together with a clear photograph of the complete original ECU label.
Which ECU is suitable for a Mercedes-Benz 2.2 CDI?
It depends on the engine version, model, production year, emissions standard and original part numbers. Several CR4.20, CR4.21 and other controllers were used in 2.2 CDI vehicles. Engine capacity alone is not sufficient.
Which ECU is suitable for a Mercedes-Benz OM642 3.0 CDI?
Compare the complete Mercedes-Benz A-number, manufacturer number, ECU family, hardware and software. Different OM642 applications may use controllers that are not interchangeable.
Can an ISM or transmission fault cause Mercedes-Benz ECU errors?
Yes. The engine ECU communicates with the transmission controller, ISM and drive authorisation system. CAN faults, a defective selector module or missing transmission adaptation can cause no-start, gear-selection and communication errors.
Does a no-start condition always mean the engine ECU is faulty?
No. A no-start condition may also be caused by missing power or ground, wiring damage, CAN communication faults, key or EIS/EZS problems, transmission authorisation faults, fuel-system defects or another failed electronic module.
What information should I send before ordering?
Send a photograph of the complete ECU label, the VIN, vehicle model and generation, production year, engine code and capacity, power output, gearbox type and diagnostic fault codes.