P0390

Camshaft Position Sensor B Circuit Bank 2

Q: Is it safe to drive with P0390?

Use caution. The engine may stall or become hard to start, and on some vehicles it won't start at all. Diagnose it before depending on the car.

Q: Can I just clear P0390?

It will return until the sensor, wiring, or connection is repaired — and may leave you unable to restart.

Camshaft position sensor Generic OBD-II High

What it means

P0390 means the engine computer sees a problem in the circuit for camshaft position sensor B on bank 2. This sensor reports the camshaft's position relative to the crankshaft so spark and injection are timed correctly. A fault can cause hard starting, stalling, or in some cases a no-start until the sensor or its wiring is repaired.

High

Can I keep driving? Driveable in some cases, but a lost cam signal can cause stalling, hard starting, or a no-start. Have it diagnosed before relying on the car.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Hard starting, extended cranking, or no-start
Stalling or rough idle
Hesitation and reduced power

Common causes

Most likely first

Faulty camshaft position sensor B (bank 2)Likely
Damaged or corroded wiring in the sensor circuitCommon
Loose or backed-out connector at the sensorCommon
Damaged reluctor/tone wheel or excessive air gapLess often
Failed ECM (rare — check the sensor and wiring first)Less often

How to diagnose & fix

Work through it in order

Read freeze-frame data and confirm the code is on the bank 2 'B' cam sensor.
Inspect the sensor connector and harness for corrosion, chafing, or loose pins.
Check the sensor tip, mounting, and air gap; look for a damaged tone wheel.
Test the sensor's signal, power, and ground with a scan tool or scope while cranking.
Replace the camshaft position sensor if its signal is missing or out of spec, then clear and re-test.

FAQ

Quick answers

Is it safe to drive with P0390?+

Use caution. The engine may stall or become hard to start, and on some vehicles it won't start at all. Diagnose it before depending on the car.

Can I just clear P0390?+

It will return until the sensor, wiring, or connection is repaired — and may leave you unable to restart.

Read & clear P0390 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX