Sensors and valves are critical components within vehicle engine management, chassis, and body control systems. Sensors monitor physical parameters like temperature, pressure, position, and speed, converting them into electrical signals for the Engine Control Unit (ECU) or other control modules. Valves regulate the flow of fluids – fuel, air, coolant, oil, exhaust gases – based on electronic signals. Modern sensors utilize technologies such as piezoelectric, Hall effect, and capacitive sensing for accuracy and durability. Valves often employ solenoid actuators for precise and rapid control, and may incorporate pulse-width modulation (PWM) for variable flow rates. Failures within this category typically manifest as drivability issues, emissions faults, or system malfunctions detectable via diagnostic trouble codes (DTCs).