BMW MOTRONIC Emission Control System

• Description
• Operation
  • MOTRONIC Control Unit (MCU)
  • Data Sensors
    • Oxygen Sensor
    • Air Flow Sensor
    • Throttle Position Sensor
    • Engine Speed Sensor
    • Reference Point Pick-Up Sensor
    • Coolant Temperature Sensors
• Testing
  • Notes
  • Preliminary Testing
  • Test Equipment
  • Test 1: Fuel Pressure
    • No Fuel Pressure
    • Fuel Pressure Too High
    • Fuel Pressure Too Low
  • Test 2: Fuel Injectors
  • Test 3: MOTRONIC Control Unit
  • Test 4: Cold Start Valve
    • Valve Does Not Open
    • Valve Leaks
  • Test 5: Idle Control Valve
  • Test 6: Idle Control Unit
  • Test 7: Engine Speed Sensor & Reference Point Pick-Up
  • Test 8: Air Flow Sensor
  • Test 9: Throttle Position Sensor
  • Test 10: Coolant Temp. Sensor
  • Test 11: Coolant Temp. Switch
  • Test 12: THERMO Timer
  • Test 13: Air Temperature Sensor
• Maintenance
  • Oxygen Sensor