Electronic Control Unit (ECU)
ECU of Volkswagen models is found behind plenum panel on driver's side of vehicle. Ambient temperature around ECU must not exceed 180°F (85°C).
With ignition switched on, ECU is connected to battery voltage. To prevent voltage fluctuations when vehicle components are switched on, ECU is provided with voltage stabilizer circuit. Operating voltage is 8 volts.
ECU unit utilizes various input signals to control fuel delivery and control exhaust emissions. Output signals are sent to differential pressure regulator and to idle speed control valve.