P0337 code definition

This trouble code means that the vehicle’s crankshaft is suffering because of low voltage.

What the P0337 code means

In order for a vehicle to propel itself forward, three things are needed:

  • Fuel
  • Air
  • Spark

In modern vehicles, a third component is at work too: the ECM (Engine Control Module). To put it simply, this high-tech device is at work measuring how much fuel must be injected relative to the measured mass of air at any time. Then, it forces a spark in order to ignite a power stroke. This entire process happens hundreds of times per second.

Obviously, precise timing is necessary to pull this off over and over and over. That’s where the crankshaft and camshaft position sensors (CMP and CKP, respectively) come into play.

The CKP carries out two very important functions. It serves as a speed sensor, for one thing. The ECM relies on it for calculating the engine speed in RPM (Revolutions Per Minute). The second important function served by the CKP is as a position sensor. This makes it possible for the ECM to figure out the position of cylinder one at what’s called top-dead-center (TDC). With RPM and TDC, the ECU can maneuver the precise function we described above that’s required for a vehicle to work.

When the ECU can’t sense sufficient voltage from the CKP sensor, the P0337 code will be stored.

What causes the P0337 code?

There could actually be a number of causes behind this code, but the most common are:

  • The CKP sensor has malfunctioned or quit working altogether
  • The sensor is no longer aligned properly
  • The starter is defective or the battery is dead
  • Electrical problems like short circuits

What are the symptoms of the P0337 code?

You most likely have a P0337 problem on your hands if you experience any of the following:

  • The engine won’t start or takes a long time to do so
  • Poor fuel economy
  • Lack of power from the engine
  • Trouble accelerating
  • An engine that misfires
  • An engine that stalls

How does a mechanic diagnose the P0337 code?

Here’s how a mechanic should diagnose this problem:

  • Using the OBD-II scanner to find out which codes have been stored
  • Checking the sensors with an eye out for a misaligned gap
  • Inspecting the battery
  • Checking for short circuits and other electrical problems

Common mistakes when diagnosing the P0337 code

A lot of mechanics will replace the sensor if it’s clearly responsible as this is easy enough to do and not incredibly expensive. At most, it will cost around $100 for this part. That being said, replacement isn’t always necessary and the sensor could be fixed with nothing more than a bit of soldering.

Also, the engine needs to be checked to ensure it’s cranking over properly. The same goes for inspecting the battery. Just because it’s “working” doesn’t mean it’s working as it should.

How serious is the P0337 code?

This code doesn’t represent a problem that could get anyone hurt, but it could make starting your vehicle impossible. Even if you can get the engine to turn over, P0337 problems could end up costing you every time you fill up.

What repairs can fix the P0337 code?

More likely than not, a sensor will need to be repaired. If it does need to be replaced, the good news is that it shouldn’t cost much. There could be other electrical problems that will require replacements, but again, your budget shouldn’t hurt too much.

Additional comments for consideration regarding the P0337 code

This isn’t the kind of problem that should be ignored because it’s not nearly as severe as other common vehicle issues. As we’ve touched on above, it’s generally pretty affordable to fix P0337 problems too.

Need help with a P0337 code?

YourMechanic will actually send a certified mobile mechanic to your home or place of business to assess and repair your vehicle. We’re happy to provide you a quote upfront or schedule an appointment online to learn more about our services. We also invite you to speak with a service advisor by calling us at 1-800-701-6230.

This article originally appeared on YourMechanic.com as P0337 OBD-II Trouble Code: Crankshaft Position Sensor A Circuit Low Input and was authored by Valerie Johnston.


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