Comprehensive Component Monitoring

EMISSION CONTROL FUNCTION MONITORING & COMPREHENSIVE COMPONENT MONITORING

OBD II regulations are based on section 1968.1 of Title 13, California Code of Regulations (CCR), The law set forth in section 1968.1 requires an increased scope of monitoring emission related control functions including:

Catalyst Monitoring

Heated Catalyst Monitoring (not currently used on BMW vehicles)

Misfire Monitoring

Evaporative System Monitoring

Secondary Air System Monitoring

Air Conditioning System Refrigerant Monitoring (Not applicable for BMW vehicles)

Fuel System Monitoring

Oxygen Sensor Monitoring

Exhaust Gas Recirculation (EGR) System Monitoring (Not applicable for BMW vehicles)

Positive Crankcase Ventilation (PCV) System Monitoring (Not required at this time).

Thermostat Monitoring (Not required at this time)

Monitoring these emission requirements is a function of the engine control module which uses "Data Sets" while monitoring the conditions of the environment and the operation of the engine using existing input sensors and output actuators.

The data sets are programmed reference values the engine control module refers to when a specific monitoring procedure is occurring. If the control module cannot determine the environmental and/or engine operating conditions due to an impaired or missing signal, it will set a fault and illuminate the Check Engine Light.

This input or control signal monitoring falls under another category called: "Comprehensive Component Monitoring".

The control module must recognize the loss or impairment of the signal or component. It determines a faulted signal or sensor via three conditions:

1. Signal or component shorted to ground.

2. Signal or component shorted to B+.

3. Signal or component lost (open circuit).

Specific fault codes are used to alert the diagnostician of these conditions.