Comprehensive Component Monitor Diagnostic

CARB OBD II Comprehensive Component Monitoring List of Components Intended To Illuminate MIL:

DIAGNOSTIC OPERATION
Comprehensive component monitoring diagnostics are required to monitor emissions-related input and output powertrain components. The California Air Resources Board (CARB) On Board Diagnostics II (OBD II) Comprehensive Component Monitoring List Of Components Intended To Illuminate The Malfunction Indicator Lamp (MIL) is a list of components, features or functions that could fall under this requirement.


INPUT COMPONENTS:
Input components are monitored for circuit continuity and out-of-range values. This includes rationality checking. Rationality checking refers to indicating a fault when the signal from a sensor does not seem reasonable (i.e. a Throttle Position (TP) sensor that indicates high throttle position at low engine loads or Manifold Absolute Pressure (MAP) voltage). Input components may include, but are not limited to the following sensors:

^ Vehicle Speed Sensor (VSS)
^ Crankshaft Position (CKP) sensor
^ Knock Sensor (KS)
^ TP sensor
^ Engine Coolant Temperature (ECT) sensor
^ Camshaft Position (CMP) sensor
^ MAP sensor
^ Mass Air Flow (MAF) sensor

In addition to the circuit continuity and rationality check, the ECT sensor is monitored for its ability to achieve a steady state temperature to enable closed loop fuel control.


OUTPUT COMPONENTS:
Output components are diagnosed for proper response to control module commands. Components where functional monitoring is not feasible will be monitored for circuit continuity and out-of-range values if applicable.

Output components to be monitored include, but are not limited to the following circuits:

^ Idle Air Control (IAC) Motor
^ Control module controlled EVAP Canister Purge Valve
^ Electronic transmission controls
^ A/C relay
^ Cooling fan relay
^ Vehicle speed Sensor (VSS) output
^ MIL control
^ Cruise control inhibit