P0366 OBD-II Trouble Code: Camshaft Position Sensor "B" Circuit Range/Performance (Bank 1)

check engine light

P0366 code definition

The P0366 code is defined as an incorrect voltage reading from the camshaft position sensor circuit, specifically for the engine bank 1 camshaft sensor B.

What the P0366 code means

In order to control fuel injection and ignition, the ECM detects the rate at which camshafts spin through camshaft position sensors. These sensors send a signal to the ECM within the first few seconds of ignition. The ECM compares the data to the manufacturer’s specifications, and if the values are off by more than 10% (either high or low), the ECM assumes that there is a fault in the camshaft. The signal is sent to the PCM, which stores the P0366 code.

What causes the P0366 code?

The most likely cause of an abnormal voltage reading in the camshaft position sensor circuit is oil or engine fluid that has leaked onto electrical components and caused shortages, or has caused the camshaft position sensor to go bad.

Other causes may include:

  • Faulty crankshaft sensor
  • Shorted or open wiring
  • Damaged electrical connectors
  • Faulty starter motor
  • Faulty starting system circuit
  • Dead or weakened battery
  • Open or shorted camshaft position sensor harness

What are the symptoms of the P0366 code?

In addition to the illumination of the Check Engine light, the P0366 code will usually be preceded by delayed engine starting, an inability to accelerate smoothly, rough idle, an overall decrease in engine performance, or a stalled engine.

How does a mechanic diagnose the P0366 code?

After an OBD-II scanner verifies the P0366 code, a mechanic should begin with a visual inspection of all the wiring, connectors, and other electrical components. Any damaged elements should be replaced, reconnected, or repaired as necessary. They should then clear the code and retest the system. If the code is stored in the PCM again, there is a fault that needs a more in-depth diagnosis and repair.

Common mistakes when diagnosing the P0366 code

If the PCM has stored the P0366 code, technicians may immediately assume that the camshaft position sensor, or the sensor circuit, is faulty, and will replace these items before performing a thorough diagnosis. However, the most common cause of this code may be an oil leak or engine fluid leak, and replacing these parts will result in the code returning once the liquid has damaged the new parts.

How serious is the P0366 code?

If the P0366 code is being detected, it is important to seek a repair as soon as possible. Without the ability to properly control fuel injection and ignition, the vehicle will not perform as it should. In addition to decreased power and rough handling, the car may simply lose power altogether and enter a no start condition. Repairing the cause of this code is important for maintaining driveability.

What repairs can fix the P0366 code?

There are many ways that a technician can address a P0366 code detection. They include:

After each repair is attempted, the code should be cleared from the PCM and the system should be retested. This procedure helps pinpoint the exact cause of the code, and ensures that the system has been properly repaired.

Additional comments for consideration regarding the P0366 code

When replacing camshaft position sensors, sensor circuits, or other components, most manufacturers recommend replacing the same part in the crankshaft system. These parts work best when they have the same amount of wear.

Need help with a P0366 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

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

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