Comprehensive Component Monitor Diagnostic

Comprehensive component monitoring diagnostics are required to monitor emissions-related input and output powertrain components.

Input Components

The PCM 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, such as 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 (VSS) Sensor
^ Mass Air Flow (MAF) sensor
^ Intake Air Temperature (IAT) sensor
^ Crankshaft Position (CKP) sensor
^ Knock Sensor (KS)
^ Throttle Position (TP) sensor
^ Engine Coolant Temperature (ECT) sensor
^ Camshaft Position (CMP) sensor
^ Manifold Absolute Pressure (MAP) 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

Diagnose the output components for the proper response to PCM 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 EVAP system
^ The electronic transmission controls
^ The A/C relay, if so equipped
^ The Vehicle Speed Sensor (VSS) output
^ The Malfunction Indicator Lamp (MIL) control
^ The cruise control enable, if so equipped