P0390 medium Severity

P0390: Camshaft Position Sensor B Circuit Malfunction (Bank 2)

Potential rough idle, reduced engine performance, possible no-start or stalling conditions

Overview

P0390 is an OBD-II generic powertrain code indicating an electrical circuit malfunction for the camshaft position sensor 'B' on engine Bank 2, often involving sensor failure, wiring/circuit issues, or timing problems

Common Symptoms

  • Check Engine light illuminated
  • Engine misfires or rough idling
  • Decreased engine performance or power
  • Difficulty starting or no-start condition
  • Poor fuel economy

Most Common Causes

Faulty camshaft position sensor B (Bank 2) high

Sensor failure or internal electrical fault prevents proper signal to PCM

Wiring harness or connector damage in camshaft sensor circuit high

Abrasion, corrosion, broken/shorted wires interrupt signal path

Open or short in the sensor circuit medium

Circuit continuity issues due to connector corrosion or insulation failure

PCM (engine control module) malfunction low

Rare, internal PCM circuit fault misinterprets sensor signals

Mechanical timing component issue (timing chain/belt misalignment) low

Severe cam/crank timing faults can mimic sensor circuit errors

Diagnostic Steps

  1. Verify P0390 with OBD-II scanner and check for additional codes
    Expected: P0390 appears, possibly with related cam/crank sensor codes
    Interpretation: Confirms sensor B circuit malfunction and reveals related faults
  2. Visually inspect wiring and connectors of camshaft position sensor B
    Expected: No damaged wires, corrosion, loose connectors
    Interpretation: Damaged wiring or connectors likely cause if faults found
  3. Measure sensor supply voltage and signal with a multimeter
    Expected: Proper reference voltage and signal waveform present
    Interpretation: No voltage/signal indicates sensor or circuit fault
  4. Swap with known good sensor or perform bench test
    Expected: Correct sensor output when tested
    Interpretation: Sensor confirmed faulty if bench test fails
  5. Check timing components for alignment if electrical tests pass
    Expected: Correct cam/crank timing alignment
    Interpretation: Timing issues may mimic sensor circuit faults if misaligned

Repair Solutions

Replace camshaft position sensor B medium
Estimated Cost: $80 - $300

Use OEM-equivalent sensor and clear codes after installation

Repair or replace wiring/connectors in sensor circuit medium
Estimated Cost: $50 - $200

Clean corrosion, solder/heat-shrink joints as needed

Repair PCM or replace if faulty hard
Estimated Cost: $400 - $1200

Rare; verify with professional scan and confirmation

Correct timing chain/belt alignment hard
Estimated Cost: $300 - $1500

Depends on engine design; related codes often present

Common Misdiagnoses

Avoid these common diagnostic mistakes:

  • Assuming only sensor replacement without checking wiring/circuit continuity

Frequently Asked Questions

What does a P0390 diagnostic trouble code signify?

Technically, the P0390 code represents Camshaft Position Sensor B Circuit Malfunction (Bank 2). It usually points to a fault within the Sensors.

Reflecting on severity: How bad is P0390?

You should treat P0390 as a medium issue. Potential rough idle, reduced engine performance, possible no-start or stalling conditions

What are the symptoms of P0390?

The most typical signs are: Check Engine light illuminated, Engine misfires or rough idling, Decreased engine performance or power.

Common triggers for the P0390 error

The most common causes are: Faulty camshaft position sensor B (Bank 2), Wiring harness or connector damage in camshaft sensor circuit, Open or short in the sensor circuit.

Repair cost breakdown for P0390

Expect to pay around $200 if the issue is a Repair or replace wiring/connectors in sensor circuit, but up to $1500 if the Correct timing chain/belt alignment needs replacement.

Does code P0390 apply to Chevrolet vehicles?

P0390 is not specific to any one brand. It can appear on Ford, Dodge, Toyota, Honda, Jeep, and other vehicles.

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