All Sensors Used in Car Engine – Complete List with Functions

  All Sensors Used in Car Engine (Full List + Functions)
 Introduction

Modern car engines rely heavily on various sensors to monitor and optimize engine performance, fuel efficiency, and emissions. These sensors provide real-time data to the Engine Control Unit (ECU), which adjusts parameters for smooth and efficient operation. This blog covers all the key sensors used in a car engine, their functions, and how they work.

 Table of Contents

1. Oxygen Sensor (O2 Sensor)

2. Mass Air Flow Sensor (MAF)

3. Throttle Position Sensor (TPS)

4. Engine Coolant Temperature Sensor (ECT)

5. Manifold Absolute Pressure Sensor (MAP)

6. Crankshaft Position Sensor (CKP)

7. Camshaft Position Sensor (CMP)

8. Knock Sensor (KS)

9. Intake Air Temperature Sensor (IAT)

10. Vehicle Speed Sensor (VSS)

11. Exhaust Gas Recirculation (EGR) Valve Position Sensor

12. Fuel Pressure Sensor

13. Oil Pressure Sensor

14. Conclusion

15. FAQs

 1. Oxygen Sensor (O2 Sensor)

Function: Measures the amount of oxygen in the exhaust gases.

Purpose: Helps the ECU adjust the air-fuel mixture for optimal combustion and reduced emissions.

Location: Exhaust manifold or pipe.

How it Works: Generates a voltage based on oxygen levels to indicate if the mixture is rich or lean.

2. Mass Air Flow Sensor (MAF)

Function: Measures the volume and density of air entering the

engine.

Purpose: Allows the ECU to calculate the correct amount of fuel to inject.

Location: Air intake system, between air filter and throttle body.

How it Works: Uses a heated wire or film; airflow cools it down, changing its resistance.

 3. Throttle Position Sensor (TPS)

Function: Measures the position of the throttle valve.

Purpose: Helps ECU adjust fuel injection and ignition

 timing according to throttle input.

Location:Throttle body shaft.

How it Works: Sends voltage signals based on throttle angle.

 4. Engine Coolant Temperature Sensor (ECT)

Function: Measures engine coolant temperature.

Purpose: Helps ECU adjust fuel mixture, ignition timing, and fan operation.

Location: Engine block or cylinder head.

How it Works: Varies resistance with temperature changes.

5. Manifold Absolute Pressure Sensor (MAP)

Function: Measures the pressure inside the intake manifold.

Purpose: Helps ECU calculate engine load for fuel and ignition adjustments.

Location: Intake manifold.

How it Works: Measures vacuum pressure; higher vacuum means lower load.

6. Crankshaft Position Sensor (CKP)

Function: Monitors crankshaft rotation speed and position.

Purpose: Critical for ignition timing and fuel injection.

Location: Near the crankshaft pulley or flywheel.

How it Works: Detects teeth on a reluctor wheel; sends pulses to ECU.

7. Camshaft Position Sensor (CMP)

Function: Detects camshaft position and speed.

Purpose: Helps ECU determine valve timing and fuel injection sequence.

Location: Near camshaft.

How it Works: Sends signals synchronized with camshaft rotation.

8. Knock Sensor (KS)

Function: Detects engine knocking or pinging.

Purpose: Allows ECU to adjust ignition timing to prevent engine damage.

Location: Engine block or cylinder head.

How it Works: Picks up vibrations caused by knocking.

9. Intake Air Temperature Sensor (IAT)

Function: Measures temperature of incoming air.

Purpose: Helps ECU adjust fuel mixture for air density changes.

Location: Air intake duct or manifold.

How it Works: Changes resistance with air temperature.

10. Vehicle Speed Sensor (VSS)

Function: Measures vehicle speed.

Purpose: Provides data for speedometer, transmission control, and cruise control.

Location: Transmission or wheel hub.

How it Works: Sends pulses relative to wheel rotation speed.

11. Exhaust Gas Recirculation (EGR) Valve Position Sensor

Function: Monitors position of the EGR valve.

Purpose: Helps control recirculation of exhaust gases to reduce emissions.

Location: EGR valve.

How it Works: Sends position signals to ECU.

12. Fuel Pressure Sensor

Function: Measures fuel pressure in the fuel rail.

Purpose: Ensures correct fuel delivery pressure.

Location: Fuel rail.

How it Works: Sends pressure data to ECU.

13. Oil Pressure Sensor

Function: Measures engine oil pressure.

Purpose: Alerts driver and ECU about oil system health.

Location: Engine block.

How it Works: Sends voltage based on pressure.

FAQs

Q1: Why are sensors important in a car engine?

A: Sensors provide vital information to the ECU, ensuring optimal engine performance, fuel efficiency, and reduced emissions.

Q2: Can a faulty sensor cause engine problems?

A: Yes, malfunctioning sensors can cause poor performance, increased fuel consumption, and emission issues.

Q3: How do I know if a sensor is faulty?

A: Common signs include check engine light, rough idling, poor acceleration, or failed emissions tests.

Q4: Can I replace sensors myself?

A: Some sensors are easy to replace, but it's best 

to consult a mechanic for proper diagnosis and replacement.