What Sensors Can Cause a Car Not To Start?

There are affiliate links on this article. If you make a purchase through any of the links, I may earn a small commission at no extra cost to you.

A failing sensor can cause several anomalies in a vehicle, making driving somewhat difficult. Even so, some sensors, when they fail, can prevent the engine from starting. But what sensors can cause a car not to start?

MAP sensors, MAF sensors, crankshaft sensors, and oil pressure sensors, all these sensors are liable to prevent your car from starting when they fail.

These sensors are connected to crucial components such as the fuel pump and the ECU. Hence, their failure can cause the engine not to start. Hereunder is a detailed explanation of why certain sensors can prevent a car from starting.

Can Failed Sensors Cause a Car Not To Start?

Apparently, a failed sensor could stop a car from starting. Modern cars are more complex than the older ones; in newer cars, virtually all the components are interconnected, and the central computer is more advanced.

Most sensors connect to the transmission, fuel pump, or ECU. Thus, when these sensors fail, the central computer (ECU) would not allow the car to start because it has received wrong, or no signals from the “failed” sensors. Until the ECU receives the expected “good” signals it is designed to receive, it won’t let your car start up.

What Sensors Can Cause a Car Not To Start?

What Sensors Can Cause a Car Not To Start

Below are some of the primary sensors that can cause a car not to start!

1. Crankshaft Sensor (Crank Angle Sensor)

This is one of the most important sensors in autos. Its function is to measure the speed and position of the crankshaft, so as to ensure accurate combustion timing in the pistons.

If the sensor is faulty, combustion timing would be inaccurate and that can cause fatal engine damage. Hence, in the bid to prevent the engine’s internal components from being damaged due to inaccurate combustion timing, the ECU may halt your car from starting.

Note: The camshaft sensor also acts like the crankshaft sensor, and it can cause a car not to start when it fails.

2. Mass Air Flow Sensor (MAF Sensor)

Dirty MAF sensors can halt a car from starting, and here’s the cause. The MAF sensor transmits the level of airflow in the engine to the ECU. If this sensor reports the wrong airflow ratio, the ECU would stop the engine from starting due to incorrect measurement of air-fuel ratio.

Well, the MAF sensor can get clogged due to road grime or excessive carbon build-up. So, when it’s too dirty to give a correct reading, the ECU would prevent the engine from starting.

3. Throttle Position Sensor

The Throttle Position Sensor gives information about the throttle in a car. Apparently, the throttle in vehicles is a crucial component for acceleration, and if the sensor tells the ECU that the throttle is not working well, it could cause the car not to start.

A faulty throttle position sensor can also cause jerking and other symptoms too.

4. Oil Pressure Sensor

In some car models, a faulty oil pressure sensor can cause the car not to start. This sensor informs the ECU of the oil pressure level in the engine.

If this sensor tells the ECU that oil pressure is low in the engine, it can cause the car not to start. Similarly, if the sensor does not send any signal at all, the ECU would stop the car from starting.

5. Manifold Absolute Pressure (MAP) Sensor

This sensor works with air intake pressure to regulate air and fuel quantities for the cylinders to ignite. It measures the vacuum of the intake manifold, in relation to the barometric pressure.

The MAP sensor is a crucial component in the internal combustion engine’s electronic control system. So, its failure can cause a car not to start.


Still thinking of what sensors can cause a car not to start? Well, as I stated earlier, MAP sensors, MAF sensors, camshaft sensors, and a couple of other sensors can make a car not start.

The information relayed by these sensors is important for the effective performance of the car’s engine; hence, when they fail or get clogged, the engine won’t start. If you’re faced with a bad sensor, the best fix is to replace the sensor.

Scroll to Top