Input Components
The Powertrain Control Module (PCM) supplies a buffered voltage to the various information sensors and switches. The PCM monitors the input components for circuit continuity and out-of-range values. The PCM also provides performance checking. Performance checking refers to the PCM indicating a fault when the signal from an input does not seem reasonable (i.e. a Throttle Position (TP) sensor that indicates high throttle position at low engine loads or low manifold absolute pressure sensor voltage). The input components may include, but are not limited to the following sensors and switches:^ Vehicle Speed Sensor (VSS)
^ Crankshaft Position (CKP) sensor
^ Throttle Position (TP) sensor
^ Engine Coolant Temperature (ECT) sensor
^ Camshaft Position (CMP) sensor
^ Manifold Absolute Pressure (MAP) sensor
^ Heated Oxygen Sensors (HO2S)
^ Fuel tank pressure sensor
^ Fuel Level sensor
^ Diode Module (engine electrical loads)
^ Power Steering Pressure (PSP) switch (if equipped)
^ Transmission range switch (A/T only)
^ The A/C Compressor Control Module (A/C relay)
^ Clutch Pedal Position (CPP) switch (M/T only)
For more information on some of the PCM input components refer to Information Sensors/Switches Description.