Description
The Siemens SID 801A Engine Control Unit (ECU) is designed specifically for diesel engines, notably the 2.0 HDI powertrain found in Citroën Berlingo and compatible Peugeot vehicles. This ECU plays a crucial role in managing engine functions such as fuel injection timing, air-fuel mixture regulation, and emission controls to optimize performance and fuel efficiency.
Commonly referenced by product codes 9647423380 and 5WS40146F-T, this ECU ensures precise electronic control over the engine’s combustion process, enhancing reliability and response under various driving conditions. It is a highly sought-after component among professional mechanics and DIY enthusiasts performing repairs or replacements on PSA group vehicles.
Replacement is typically straightforward, involving disconnection of the battery, removal of the old ECU by unplugging connectors and unscrewing fixing points, followed by installation of the new unit. It is recommended to use diagnostic tools to reprogram or synchronize the unit with the vehicle’s immobilizer system post-installation.
Failures can result from electrical faults, water ingress, or aging internal components, causing symptoms such as engine stalling, poor fuel economy, or starting difficulties. Regular inspection and timely replacement help maintain optimal engine operation.







