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P0389 OBD2: Crankshaft Position Sensor "B" Circuit Intermittent

P0389 OBD2: Crankshaft Position Sensor “B” Circuit Intermittent

The P0389 OBD-II code indicates a problem with the Crankshaft Position Sensor “B” circuit. This sensor plays a crucial role in measuring the rotational speed and position of the crankshaft, providing vital data to the Powertrain Control Module (PCM) for controlling ignition spark timing and fuel delivery.

What Does the P0389 Code Mean?

When the PCM detects an irregular signal or no signal from the Crankshaft Position Sensor, it triggers the P0389 code. This suggests that there is an intermittent fault in the sensor’s circuit, which can lead to significant engine performance issues.

What Causes the P0389 Code?

Several factors can cause the P0389 code, including:

  • Broken tone ring
  • Crankshaft Position Sensor (CKP) failure
  • Powertrain Control Module (PCM) failure
  • Wiring issues in the sensor circuit

What Are the Symptoms of the P0389 Code?

Drivers experiencing the P0389 code may notice symptoms such as:

  • Decreased engine performance
  • Engine may not start
  • Increased fuel consumption

How Serious Is the P0389 Code?

The P0389 code is considered urgent because it can lead to severe engine damage or unsafe driving conditions. Immediate attention and diagnosis are recommended to avoid further complications.

How to Diagnose the P0389 Code

Diagnosing the P0389 code typically involves the following steps:

  • Use an OBD-II scanner to confirm the P0389 code.
  • Inspect the Crankshaft Position Sensor and its wiring for visible damage.
  • Check the tone ring for any breaks or misalignment.
  • Test the sensor’s electrical signals with a multimeter.
  • Evaluate the PCM for potential faults.

Common Repairs for the P0389 Code

Common repairs associated with the P0389 code may include:

  • Replacing the Crankshaft Position Sensor
  • Repairing or replacing damaged wiring
  • Addressing issues with the tone ring
  • Replacing or reprogramming the PCM if necessary

How Much Does It Cost to Fix the P0389 Code?

The cost to fix the P0389 code can vary widely based on the make and model of the vehicle, as well as the specific repairs needed. On average, replacing a Crankshaft Position Sensor can range from $100 to $300, including parts and labor. Additional repairs may increase the total cost.

Can I Fix the P0389 Code Myself?

While some aspects of diagnosing and fixing the P0389 code can be tackled by a knowledgeable DIYer, it’s crucial to have a good understanding of automotive systems and access to the right tools. If you’re unsure, it’s best to consult with a professional mechanic to prevent further issues.

About JC Landry

JC is the Senior Editor at eManualOnline.com, GarageSpot.com, and Drive-My.com, as well as the Webmaster of TheMechanicDoctor.com, only to name a few. He's been a certified Master Mechanic for 15 years, working for various car dealers and specialized repair shops before turning towards blogging about cars and EVs in the hope of helping the next generation of automotive technicians. He also loves cats, Johnny Cash and Subarus.

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