Input Components

The PCM monitors the input components for circuit continuity and for out-of-range values. The monitoring includes performance checking. Performance checking refers to indicating a fault when the signal from a sensor does not seem reasonable, for example, a throttle position sensor that indicates a high throttle position during low engine loads or during low MAP voltage. The input components may include but are not limited to the following sensors:

• The vehicle speed (VSS) sensor
• The accelerator pedal position (APP) sensor, if the vehicle has this equipment
• The mass airflow (MAF) sensor
• The intake air temperature (IAT) sensor
• 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

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 the closed loop fuel control.