This SAGEM S2000-4A engine control unit (ECU) is intended for Peugeot 206 1.4i petrol engines and is commonly referenced by manufacturer codes and part numbers. It is a used unit suitable for professional garages and experienced DIY mechanics who need a direct replacement or a donor ECU for cloning/coding. Search terms customers often use: ECU Sagem S2000-4A, Peugeot 206 1.4i ECU, 9644625680, 9646988780, 1940W5.

Technical Information

• Manufacturer: SAGEM
• Model: S2000-4A (For Peugeot 206 1.4i)
• Product Codes: 9644625680, 9646988780, 1940W5
• Additional Numbers: 1940W6, 194456

Function and Compatibility

This unit is an engine management ECU that controls fuel injection, ignition timing, idle regulation, fuel pump control, emission-related functions and on-board diagnostics (OBD). It is suitable for Peugeot 206 1.4i petrol variants that use the SAGEM S2000-4A hardware/software family. Always verify that the listed product codes match the unit being replaced — many mechanics and owners search by part number when sourcing a replacement ECU.

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 technician with PSA service equipment (DiagBox/Lexia/PP2000).
• Before removal/installation always disconnect the battery and follow the manufacturer’s procedure to avoid damaging the unit.

Installation Recommendations

Work should be performed by a qualified mechanic or an experienced DIYer comfortable with vehicle electrics. Basic recommended steps:

• Disconnect the negative battery terminal and wait a few minutes to discharge capacitors.
• Access the ECU following vehicle-specific instructions (remove trim or engine cover as required).
• Release connector locks carefully and unplug wiring harnesses without pulling on the wires.
• Remove mounting screws/clips and fit the replacement unit securely in the original position.
• If cloning is used, perform EEPROM/Flash cloning before final installation where possible; if virginizing, perform initialization and telecoding with DiagBox and adapt keys if required.
• After installation, clear fault codes and verify proper operation: engine start, idle stability, absence of fault indicators and correct sensor readings.

How To Replace (Summary)

1. Disconnect battery negative terminal.
2. Locate ECU and remove any covers or panels.
3. Unplug connectors (unlock retention clips first) and remove the unit.
4. Install replacement unit, secure bolts/clips and reconnect harnesses.
5. Reconnect battery and perform cloning or coding as required (see Installation and Coding section).
6. Run diagnostics and road test to confirm correct function.

Reasons This Part Most Commonly Fails

• Water ingress and moisture causing corrosion or short circuits.
• Electrical surges or bad battery/alternator behavior damaging internal electronics.
• Connector corrosion or poor grounding leading to intermittent faults.
• Thermal stress and age-related component degradation after many years/miles.
• Software/data corruption or memory failure in EEPROM/Flash.

Typical Symptoms Indicating ECU Fault

• Engine will not start or starter cranks but no ignition/fuel control.
• Intermittent stalling, misfires or loss of power.
• Stable fault codes stored in the ECU and persistent Check Engine Light.
• Poor fuel economy, erratic idle or limp-home mode activation.

Note: Because this is a used control unit, correct commissioning (cloning or virginization and coding) is essential for proper operation. For reliable results use appropriate diagnostic equipment and follow PSA procedures when coding or adapting keys.