Theory and Operation: Theory/Operation

• Introduction
• Computerized Engine Controls
  • Notes
  • MCU Location
  • MOTRONIC Control Unit (MCU)
  • Input Devices
    • Notes
    • A/C Switch
    • Airflow Meter & Air Temperature Sensor
    • Coolant Temperature Sensor or Switch
    • Cranking Signal
    • Cylinder Identification Sensor
    • Engine Speed/Reference Point Sensor
    • Main Relay (Battery)
    • Oxygen Sensor (Lambda Signal)
    • Throttle (Position) Switch
    • Transmission Range Selector (A/T Only)
    • Vehicle (Road) Speed Sensor
  • Output Signals
• Relays
• Fuel System
  • Fuel Delivery
    • Fuel Pump
    • Fuel Pump Relay
    • Fuel Pressure Regulator
  • Fuel Control
    • Cold Starting
    • Half-Sequential Fuel Injection
    • Adaptive Lambda Control (Oxygen Sensor) System
    • Oxygen Sensor Heater Relay (3 & 5 Series Only)
  • Idle Speed
    • Adaptive Idle Speed Regulation
• Ignition System
  • Ignition & Timing Control System
• Emission Systems
  • Evaporative Emission Control System
  • Fuel Evaporative Control Valve
• Self-Diagnostic System
  • Diagnostic System (3, 5 & 7 Series)
  • Check Engine Light