New or Revised Hardware For OBD II

The major system changes needed to implement OBD II take place on the software side but there are some additions and modifications to the hardware as well. The following list covers electrical/electronic components. The non-electronic components would form an even longer list although most of the changes would not be readily apparent as they tend to take the form of upgraded hoses, better check valves and so on.

The following components are completely new:
- Post-catalyst Heated Oxygen Sensor, used on all models. This sensor has a fourth wire providing a sensor reference ground and is easily identified by the small vent slots on the working end of the sensor.
- Fuel Tank Pressure Sensor, initially used on 900 V6 models and on all 900s by M96.5. Mounted on the filler pipe above the rear axle.
- Canister Close Valve, used on 900 (at first just V6) models. This solenoid valve is connected to a redesigned EVAP canister.
- Vehicle Vertical Acceleration Sensor, found on 4.1 (4 cyl.) MOTRONIC models. Located behind the upper mount for the driver's side front strut.

The following components have redesigned connectors or upgraded contacts:
- All MOTRONIC Knock Sensors
- All MOTRONIC Crankshaft Position Sensors
- 5.2 MOTRONIC Camshaft Position Sensor
- All Engine Coolant Temperature Sensors
- TRIONIC & 5.2 MOTRONIC Intake Air Temperature Sensors
- All Throttle Position Sensors
- 5.2 MOTRONIC Ignition Coil

IAC Valves Have Been Modified as follows:
- The 900 V6 MOTRONIC system now uses a three wire IAC valve.
- All MOTRONIC IAC valves have an increased air-flow capacity