Skip the auto shop - Our mechanics make house calls

Can a Bad Sensor Prevent a Car From Starting?

Sensor

You go outside to start your car and leave for work. When you turn the ignition, nothing happens. Besides being incredibly frustrated at being late for work, you may be scratching your head, trying to figure out what’s going on. You may not have had any signs of a problem, but now your vehicle isn’t going anywhere. A bad sensor could be the culprit.

Which sensors prevent the engine from starting?

Faulty sensors can keep your engine from starting as a safety measure. For instance, the crank angle sensor, or crankshaft position sensor, may be located near the transmission belt housing and come in contact with water, which would prevent it from working. This sensor measures the position of the crankshaft and the speed to ensure the pistons are timed for the right amount of combustion at the right time. If the information isn’t sent to the engine computer, nothing will happen when you try to start the car.

Another sensor that will impact whether your vehicle starts is the mass airflow (MAF) sensor. The function of this sensor is to let the computer know how much air is in the engine. As more comes in, more fuel is also needed to maintain optimal ratios. Without the correct ratio, the engine won’t run.

The oil pressure sensor on some models may prevent your car from starting if it isn’t working correctly. This sensor lets the computer know the correct oil pressure is present. If it sends a signal that the pressure is low, the computer may prevent the engine from starting. If the signal was sent in error or no signal sent at all, it may indicate you have a bad sensor.

Have a professional mechanic test your sensors if you think one of them is causing the problem. It can be replaced and you will be back on the road.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P0291OBD-II Trouble Code: Cylinder 11 Injector Circuit Low
P0291 code definition When your vehicle’s PCM registers the P0291 code, it means that a voltage reading came from the fuel injector circuit – for cylinder number 11’s fuel injector –...


Related questions

Q: Motor idles fine, when you give it gas it bogged down, already changed the plugs,wires,distributor cap and rotor

Hi there, thanks for writing in about your Chevrolet C1500. It's highly likely the mass airflow sensor is bad. To verify, a scan tool should be connected and observe voltage changes in the mass airflow sensor readings. Same for oxygen...

Q: No tire pressure sensor, disappointing

The tire pressure sensor light alerts you when a tire has low pressure. When you get your tire fixed, the light goes out. This is how it's supposed function when everything is working properly. When the system malfunctions, you may...

Q: P0171 and P0174 codes

For one, these codes are for a lean condition and are not O2 sensor specific codes. It is true that some of the newer Fords have an issue with the purge valve staying on, putting a vacuum on the system...