Comprehensive Component Monitor Diagnostic Operation
Comprehensive Component Monitor DiagnosticThe comprehensive component monitoring diagnostics are required to monitor emissions-related input and output Powertrain components. The CARB OBD II Comprehensive Component Monitoring List of Components intended To Illuminate the MIL is a list of components, features or functions that could fall under this requirement.
Input Components
The control module monitors the input components for circuit continuity and out-of-range values. This includes performance checking. Performance 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 MAP voltage). The input components may include but are not limited to the following sensors:
- The Vehicle Speed Sensor (VSS)
- The Crankshaft Position (CKP) sensor
- The Knock Sensor (KS)
- The Throttle Position (TP) sensor
- The Engine Coolant Temperature (ECT) sensor
- The Camshaft Position (CMP) sensor
- The Manifold Absolute Pressure (MAP) sensor
- The 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 in order to enable a closed loop fuel control.
Output Components
The Output Components respond 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:
- The Idle Air Control (IAC) Motor
- The Control module controlled EVAP Canister Purge Valve
- The Electronic transmission controls
- The A/C relay
- The Cooling fan relay
- The VSS output
- The MIL control
- The Cruise control inhibit
California Air Resources Board (CARB) OBD II Comprehensive Component Monitoring List of Components Intended to Illuminate MIL
IMPORTANT: Not all vehicles have these components.