How To Start A Car With A Bad Crankshaft Sensor?

Can A Bad Crankshaft Sensor Cause No Start?

Yes, among other things bad crankshaft sensor cause no start. As you learned already, the task of a crankshaft position sensor is to regulate the speed and the rotational position of the crankshaft.

For the same purpose, this sensor often has to send signals to the Engine Control Unit to make necessary adjustments where needed.

While cranking the engine, the RPM signal from the sensor goes to the Ignition Module or the PCM that controls the on and offing of the ignition coil.

In case there is a faulty signal or an absence of it, the ignition coils may not spark, thereby causing the car not to start.

Will A Bad Crankshaft Position Sensor Cause No Crank No Start?

If your gas mileage is significantly lower than normal, this means that your crankshaft position sensor is faulty, which could cause the engine to not start or not crank. Engine misfires, engine stall completely, or no crank/no start are all possible results of faulty sensors.

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Rough Idling

You might feel that the engine runs rough or vibrates at idle, say, when you’re sitting at a red light. This is similar to the above in that it stems from poor spark timing.

What Sensors Can Stop A Car From Starting?

What sensors prevent the engine from starting? It is possible for faulty sensors to prevent your engine from starting. Water may cause the crank angle sensor, or crankshaft position sensor, to malfunction if it is located near the transmission belt housing.

 Can I Start a Vehicle with a Bad Crank Sensor?

Whether or not you can start a car with a bad crank sensor will depend on the car model. Some vehicles, especially older ones with simpler engine electronic systems, only use the CKP sensor to monitor the engine for misfires. On these cars, it might take a little more cranks to start the engine, the check engine light might start flashing or, at least, illuminate, but it should start just fine.

With modern vehicles, however, it might not be possible since they rely heavily on electronics. In most cases, the PCM may cancel the ignition or fuel injection system to prevent the engine from starting.

5. Engine Misfires or Vibrates

Should you feel or hear a brief stutter in the engine, it may be a sign of misfiring cylinders from a bad crankshaft position sensor. A failing crankshaft position sensor cannot provide the right information about piston positioning in the engine, causing a cylinder to misfire. This could also occur from faulty spark plug timing, but if the spark plug checks out, then the crankshaft sensor is likely the source.

1. Run a diagnostic check using a code reader

This will tell you if there are any faulty engine sensors causing the engine to cut out. Faulty engine sensors such as the camshaft, crankshaft, manifold absolute pressure and fuel pressure sensors can cause an engine to stall right after starting.

To begin with, I always start by hooking up a diagnostic reader to see if there are any error codes stored in the ECU. If the check engine light has come on, then this usually means that an error code has been stored. This can really help get to the source of the problem quickly, and often without getting your hands dirty!

Some common error codes that may show up include:

  1. P0340 Camshaft Position Sensor Circuit Malfunction
  2. P0010 “A” Camshaft Position Actuator Circuit (Bank 1)
  3. P0345 Camshaft Position Sensor A Circuit Malfunction (Bank 2)
  4. P0300 Random Misfire Detected Code
  5. P0174 System too lean (Bank 2)
  6. P0171 System Too Lean (Bank 1)
  7. P0190 Fuel Rail Pressure Sensor Circuit Malfunction
  8. P0191 Fuel Rail Pressure Sensor Circuit Range/Performance
  9. P0600 Serial Communication Link Malfunction
  10. P0335 Crankshaft Position Sensor “A” Circuit Malfunction

Depending on what error code(s) show up, you may need to remove some engine parts or sensors to figure out whats going on.

How To Start A Car With A Bad Crankshaft Sensor?

In order to start a car with a bad crankshaft sensor, you have to do two things first: locate the crankshaft position and then start the car.

Locating The Position of Crankshaft Sensor

Depending on the model of the car you own, and of course the year of its manufacturing, the location of the crankshaft position sensor will differ.

As you would expect by the name, this sensor will be placed near the engine crankshaft.

So check for it to the front or back of the engine cylinder block or even to the sides of it.

In some cars, this sensor may be located near the harmonic balancer or the main pulley, as you see in Fords.

However, it may also be positioned in the transmission bell housing, as they are made to regulate the speed of the clutch flywheel.

You would be better off checking the manual for the CKP as the position can be different even when your vehicles have been produced by the same manufacturer!

Starting The Car

Now, whether you will be able to start the car or not will heavily depend on how severely the crankshaft sensor has been damaged.

If you can’t reach a mechanic at the moment but need the ride desperately, you can attempt to start the car, even with a bad crankshaft position sensor.

However, keep in mind that even after following the steps, your car may not start. All you need to do here is:

  1. Locate the CKP sensor in your car’s engine.
  2. Remove the sensor plug of the crankshaft position sensor.
  3. Use a starting fluid like STA-BIL for an easy, corrosion-free start.
  4. After the application of the fuel stabilizer, try to start your car.
  5. If you find the engine to start upon conducting these steps and then switch off all of a sudden, there may be an additional issue regarding your car’s fuel pump. In that case, check if you have enough fuel.
  6. If your car does not start at all, then it may be an issue with the spark plugs. In that circumstance, you should seek professional help, as the CKP sensor might need a replacement before you get to start your car again.

How Do I Test A Crankshaft Sensor? 

Trouble Codes the ‘Check Engine Light’ 

If you are experiencing that “check engine light” being on, then your ECU or your engine control unit has documented some kind of trouble code/alert. Check the diagnostic codes with your diagnostic scan tool. The trouble codes that are between P0335 and P0338 are in direct correspondence to the to crankshaft sensor. This test is probably one of the most accurate to perform. But the unfortunate side to this test, is that there is a great chance that your crankshaft sensor is very worn by the time the “check engine light” illuminates from your dashboard.  

Crank Sensor Test 

The next test you can perform requires that you get your diagnostic scan tool. One of the settings of your tool gives you a reading of your vehicle’s engine speed in RPMs or in revolutions per minute. Since the scanner gets its data from the crankshaft position sensor, you want to make sure that the scanner can read the engine RPM as the engine cranks. Your scan tool should have an output between 100 and 500 revolutions per minute or RPMs. If you don’t have this reading, then you have a faulty crankshaft sensor. For a reading of zero, you have a crankshaft sensor that has completely failed. 

Using a Multimeter 

We get that not everyone has a scan tool handy. So, another way you can test your crankshaft sensor is to use a multimeter, which are far more common than the scan tool. They are quite handy in diagnosing a multitude of electronic parts- and they can also measure current, resistance and voltage. Remove the crankshaft sensor and then test for resistance. Place one end of the multimeter to each of the wiring leads of the sensor. If you have a reading of zero resistance, then you have a short circuit. If you have a reading of infinite resistance then you have an open circuit. But regardless of if you have a reading of zero of infinite resistance, then “all roads lead” to a faulty crankshaft sensor. If you have any other reading, check that reading against the manufacturer’s recommendations and specifications. You can also check your crankshaft sensor with your multimeter – and use it to evaluate the output voltage while the engine cranks. You will need help to do this test. 

Carefully probe the wiring connectors and calculate the output voltage in AC millivolts. While a common reading is about 200 millivolts, this will vary, depending on your car. For a reading that has no output voltage, then you know that your crankshaft sensor is bad. 

With these tests, you can find the source of your problem.  These tests will also confirm that you either have to visit your mechanic, or spend your time zeroing in on the issue at hand, instead of guessing. 

Next Step

Schedule Vehicle Engine Electrical Inspection

The most popular service booked by readers of this article is Vehicle Engine Electrical Inspection. Once the problem has been diagnosed, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. We currently cover over 2,000 cities and have 100k+ 5-star reviews… LEARN MORESEE PRICING & SCHEDULING

Finding Crankshaft Position Sensor (CPS)

The crankshaft position sensor is located near the coolant recovery tank and fuel filter in the engine compartment. The crankshaft position sensor on most vehicles is near the back of the engine, but it is not always easy to see because many manufacturers use plastic covers to protect it from damage or moisture.

Testing Bad Crankshaft Sensor

Using Multimeter:

The crankshaft position sensor can be tested with a multimeter. First, you will need to remove it from the engine. Then connect one lead of the multimeter to the ground and touch the tip of an alligator clip to each wire terminal in turn.

If your reading is more than 0 volts but less than 5 volts, your sensor is fine. If your reading is more than 5V, then the crankshaft position sensor requires replacement.

 Most Common Symptoms of a Bad CKP Sensor

To identify a failing CKP sensor as quickly as possible, you’ll need to first be aware of what happens when the PCM loses the sensor’s signal. To help you with that, here’s a quick list of the most common symptoms related to a faulty crankshaft sensor.

  • Crank/No Start condition: This condition happens when the engine cranks but fails to start, even after multiple tries.
  • Immediate stalling of the engine: The car does start, often after an extended cranking time, but stalls right away or moments after.
  • Lumpy idle: If the sensor is failing intermittently, the PCM will default to factory settings because of the incorrect readings, compromising fuel delivery. This condition will usually cause misfires and jerky acceleration.
  • Flashing check engine light: Once the PCM loses the CKP sensor’s signal or if the readings are out of the normal threshold, the check engine light will start to flash, and a DTC code will be recorded.

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