Input Devices: Notes

Input devices are monitored for circuit continuity and out-of-range values, which includes rationality checking. Rationality checking will indicate a fault when a sensor signal does not seem reasonable based on other input signals.

Input devices may include, but are not limited to the following sensors:

• Camshaft Position (CMP) sensor.
• Closed Throttle Position (CTP) electrical switch.
• Crankshaft Position (CKP) sensor.
• Engine Coolant Temperature (ECT) sensor. In addition to circuit continuity and rationality check, ECT sensor is monitored to ensure its ability to maintain a constant temperature, enabling closed loop fuel control.
• Fuel Level Sensor.
• Fuel Tank Pressure Sensor.
• Heated Oxygen Sensors (HO2S).
• Manifold Absolute Pressure (MAP) sensor.
• Throttle Position (TP) sensor.
• Vehicle Speed Sensor (VSS).

Vehicles are equipped with different combinations of input devices. Not all devices are used on all models. To determine input device usage on a specific model, see appropriate wiring diagram in the WIRING DIAGRAMS article. Available input signals include the following: