Startstoppkontroller

Startstoppkontroller is a control unit used in automotive start-stop systems to automatically shut down the internal combustion engine when the vehicle is stationary and restart it when movement is required. The aim is to reduce fuel consumption and emissions in urban driving, particularly at stops and in slow traffic. The controller assesses a range of conditions, including vehicle speed, brake status, gear position, engine temperature, battery voltage, and electrical load from accessories such as air conditioning. If conditions are favorable and no safety or drivability risks are present, the engine is switched off at a stop and restarted when the driver releases the brake, presses the accelerator, or when the transmission requires propulsion.

Startstoppkontrollers can be integrated within the engine control unit (ECU) or realized as a dedicated standalone module in vehicles with a mild-hybrid or Integrated Starter Generator (ISG) architecture. Most systems operate on the vehicle’s 12-volt electrical network, while some 48-volt ISG setups use the electric machine to provide faster and smoother restarts and additional power for accessories.

Key considerations include ensuring smooth restarts that do not compromise comfort, managing battery health to prevent excessive discharge, and coordinating with climate control to maintain cabin comfort without needless shutdowns. Safety mechanisms prevent shutdown during critical conditions such as engine warming, heavy loads, or when safety systems require continuous operation.

Benefits include lower fuel use and reduced emissions, especially in urban driving. Challenges involve potential perceived restart delay, battery wear concerns, and varying savings depending on driving patterns. See also: start-stop system, mild hybrid, engine management.