Crankshaft Position Sensor (CKP)

Near the crankshaft, flywheel, or crankshaft pulley, depending on engine model

Detects engine speed and crankshaft position; provides timing signals for fuel injection and engine control

Camshaft Position Sensor (CMP)

Near the camshaft or cylinder head, depending on engine design

Detects camshaft position; helps determine injection timing and cylinder synchronization

Engine Coolant Temperature Sensor (ECT)

Engine coolant passage, cylinder head, or coolant outlet

Monitors coolant temperature; helps control fuel injection, cooling fan operation, and overheat warnings

Intake Air Temperature Sensor (IAT)

Intake pipe or intake manifold

Measures incoming air temperature to help the ECU calculate air density and adjust fuel injection

Manifold Absolute Pressure Sensor (MAP)

Intake manifold or intake pressure passage

Measures intake manifold pressure; supports engine load calculation and fuel injection control

Boost Pressure Sensor

Intake manifold or turbocharger charge-air piping, depending on engine design

Monitors turbocharger boost pressure; helps control engine performance and detect abnormal boost conditions

Mass Air Flow Sensor (MAF)

Air intake duct between the air filter and engine, where equipped

Measures incoming air mass to support air-fuel management and engine control

Accelerator Pedal Position Sensor (APP)

Accelerator pedal assembly

Detects accelerator pedal input and sends the driver's torque demand to the ECU

Fuel Rail Pressure Sensor

Common rail of electronically controlled diesel fuel injection systems

Measures fuel rail pressure; helps the ECU regulate injection pressure and diagnose fuel system faults

Engine Oil Pressure Sensor / Switch

Engine oil gallery or oil filter housing, depending on engine model

Monitors engine oil pressure and activates warnings when pressure is outside the specified range

Engine Oil Temperature Sensor

Engine oil passage or oil pan area, where equipped

Measures engine oil temperature to support engine protection and control strategies

Vehicle Speed Sensor (VSS)

Transmission, output shaft, or another designated speed-sensing location, depending on model

Detects vehicle speed for instrument display, engine control, and related vehicle systems

Transmission Speed Sensor

Transmission input or output shaft area, depending on transmission design

Monitors transmission shaft speed to support gear operation, speed calculations, and fault diagnosis

Exhaust Gas Temperature Sensor (EGT)

Exhaust manifold or exhaust after-treatment system, depending on configuration

Measures exhaust temperature to protect components and support emissions control

Differential Pressure Sensor (DPF, where equipped)

Connected to pressure points before and after the diesel particulate filter

Measures pressure difference across the DPF to help determine filter restriction and regeneration requirements

NOx Sensor (where equipped)

Exhaust after-treatment system, typically before or after the SCR catalyst

Measures nitrogen oxide levels to support emissions monitoring and SCR control

Oxygen Sensor (where equipped)

Exhaust system

Measures oxygen concentration in exhaust gas for applicable engine-control and emissions systems

Water-in-Fuel Sensor

Fuel filter or fuel-water separator assembly

Detects water accumulation in diesel fuel and triggers a warning to help protect the injection system

Fuel Level Sensor

Inside the fuel tank

Measures fuel level and sends the signal to the instrument cluster

Clutch Pedal Position Switch / Sensor (where equipped)

Clutch pedal assembly

Detects clutch pedal operation for starting interlock, engine control, or cruise-control functions, depending on configuration

Brake Pedal Switch

Brake pedal assembly

Detects brake pedal application for brake lamps and applicable engine or vehicle control functions