OBD Guide

P0391

Camshaft Position Sensor B Circuit Range/Performance Bank 2

P0391 is an OBD-II diagnostic trouble code meaning: Camshaft Position Sensor B Circuit Range/Performance Bank 2. Common causes: camshaft position sensor b malfunction, open or shorted wiring harness. Estimated repair cost: $33–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$33–167 (est.)

Symptoms

  • Unstable engine operation
  • Power reduction
  • Increased fuel consumption
  • Check Engine Light Illuminates
  • Problems starting the engine

Causes

  • Camshaft Position Sensor B Malfunction
  • Open or shorted wiring harness
  • Poor contact in the sensor connector
  • Power or grounding problems
  • Mechanical timing problems (chain, gears)
  • Sensor contamination with metal shavings

How to Fix

  1. Check sensor parameters with a scanner
  2. Visually inspect the sensor and wiring harness
  3. Check the contacts in the sensor connector
  4. Measure the resistance and voltage of the sensor
  5. Replace sensor if necessary
  6. Check the condition of the timing chain and marks

Related codes

Error P0391 by Vehicle Brand

FAQ

What does the P0391 code mean?

P0391 is an OBD-II diagnostic trouble code that indicates: Camshaft Position Sensor B Circuit Range/Performance Bank 2

What causes a P0391 error code?

The most common causes of P0391 include: Camshaft Position Sensor B Malfunction; Open or shorted wiring harness; Poor contact in the sensor connector; Power or grounding problems.

How do I fix a P0391 diagnostic trouble code?

To fix P0391: Check sensor parameters with a scanner. Visually inspect the sensor and wiring harness. Check the contacts in the sensor connector. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P0391?

Limited driving only, diagnose soon

How much does it cost to fix P0391?

The estimated repair cost for P0391 is $33–167. Actual cost depends on your vehicle, location, and labor rates.

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