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.
Clutch Pedal Position (CPP) switch.
Crankshaft Position (CKP) sensor.
Diode module (engine electrical loads).
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.
Power Steering Pressure (PSP) switch.
Throttle Position (TP) sensor.
Transmission Range (TR) switch.
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 WIRING DIAGRAMS - 1.0L article. Available input signals include the following:

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Input Devices: Notes

Use the Manual With the Right Hardware

When to See a Mechanic