Description
Control Unit DELPHI DDS CMM DW10C DCM3.5 suitable for vehicles Citroën C4 Picasso 2.0 HDi 120 kW and Peugeot 3008 and 5008 2.0 HDi 120 kW
This Delphi DCM3.5 engine control unit is a direct-fit management module for the DW10C 2.0 HDi engines used in selected Citroën and Peugeot models. Frequently searched by its product numbers, the unit manages injection timing, fuel quantity and communication with other vehicle systems to ensure correct engine performance and emissions control. Designed for professional garages and competent DIY mechanics, this used control unit offers a cost-effective replacement when the original ECU fails, restoring engine drivability and fault-free sensor actuation when correctly installed and configured.
Technical Information
- Manufacturer: Delphi
- Model: DCM3.5 / DDS CMM DW10C
- Product Codes: 9666556980, 9666098180, 1677620680
- Other Numbers: 1943TH, 1943QR, 1943QS
- Applications: Citroën C4 Picasso 2.0 HDi 120 kW; Peugeot 3008 I and 5008 I 2.0 HDi 120 kW
Function And Typical Faults
The ECU controls common-rail injection parameters, processes sensor inputs (crankshaft and camshaft position, fuel pressure, air mass/pressure, temperature), and manages actuators to optimize combustion and emissions. It also exchanges data with other vehicle modules via the CAN network. Symptoms of a faulty unit include persistent engine warning lights, rough idling, loss of power, fuel delivery faults, or intermittent communication errors.
Common causes of failure are electrical damage from voltage spikes, water or moisture ingress, connector corrosion, thermal stress and broken solder joints or internal component degradation. Software corruption or mismatched immobilizer data can also prevent the unit from allowing the engine to run.
Replacement And Installation
Replacement requires careful handling and basic diagnostic tools. Typical replacement steps:
- Disconnect the negative battery terminal before any work.
- Locate the ECU (often found in the engine bay near the battery or airbox on these models).
- Release connectors and mountings, carefully remove the old unit and install the replacement in the reverse order.
- Ensure connectors and pins are clean, dry and free of corrosion before reconnecting.
- After mechanical installation, the unit will typically require cloning or coding to the vehicle for full functionality and immobilizer acceptance.
The unit is often searched for by its reference numbers above, so verify the part numbers match the one being replaced.
Installation And Coding – Important
– The Unit Is Used And Is “Paired” With The Original Vehicle (VIN/PIN/Keys).
– Commissioning Options:
1) Cloning Data From The Old Unit (EEPROM/Flash) – After Cloning The Unit Is Plug And Play.
2) Virginization And Subsequent Initialization/Telecoding Via DiagBox (Or Online) + Key Adaptation.
– Recommended To Be Performed By A Specialist With PSA Service Equipment (DiagBox/Lexia/PP2000).
– Before Removal/Installation Always Disconnect The Battery And Follow The Manufacturer Procedure To Avoid Damaging The Unit.
Recommendations For Installation
- Perform cloning or coding with appropriate diagnostic equipment to ensure immobilizer and CAN network compatibility.
- Use a static-free work area and avoid touching connector pins directly; protect the unit from moisture during installation.
- Check and clean battery earth points and ECU grounding to prevent electrical noise and potential damage.
- If the vehicle shows persistent faults after installation, review stored fault codes and live sensor data to rule out wiring, sensors or actuators that may have caused ECU failure.
- Have software updates or calibrations applied where recommended by the manufacturer to ensure optimal performance.
Why This Part Most Often Fails
Failures are typically caused by environmental exposure (water ingress, condensation), corrosion at plugs or earth points, heat cycling leading to solder joint fractures, and electrical surges from poor battery connections or jump-starts. In some cases, upstream faults such as intermittent sensor signals or short circuits can overload the unit and accelerate failure.
