P0393

Camshaft Position Sensor B Circuit High Bank 2

Q: Is it safe to drive with P0393?

Short trips are usually possible, but the engine may stall or be hard to start. Have it diagnosed before relying on the vehicle.

Q: Can I just clear P0393?

You can, but it returns until the camshaft sensor or its circuit is repaired.

Ignition / camshaft position Generic OBD-II High

What it means

P0393 means the computer sees an abnormally high voltage on the camshaft position sensor B circuit for bank 2. The cam signal helps time fuel and spark, so a bad signal can cause hard starting, rough running, or stalling — and on some vehicles a no-start. It most often traces to the sensor, a wiring short-to-voltage or open, or the reluctor ring.

High

Can I keep driving? Often driveable but the engine may run rough, hesitate, or be hard to start; on some vehicles a cam-signal fault can cause stalling or a no-start, so repair soon.

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 or extended cranking
Rough idle, hesitation, or occasional stalling
Reduced power and fuel economy

Common causes

Most likely first

Faulty camshaft position sensor B (bank 2)Likely
Signal wire shorted to voltage or an open causing a high readingCommon
Loose or corroded connector at the sensorCommon
Damaged reluctor/tone ring or excessive sensor air gapLess often
Failed engine control module (rare)Less often

How to diagnose & fix

Work through it in order

Read freeze-frame data and confirm it's the bank 2 camshaft sensor B, circuit high.
Inspect the sensor connector and wiring for a short to voltage, an open, or corrosion.
Check the sensor's reference voltage, ground, and signal, and verify correct mounting and air gap.
Inspect the reluctor ring; compare cam and crank signals for correlation with a scan tool.
Replace the sensor if the signal stays high with good wiring. Clear and re-test.

FAQ

Quick answers

Is it safe to drive with P0393?+

Short trips are usually possible, but the engine may stall or be hard to start. Have it diagnosed before relying on the vehicle.

Can I just clear P0393?+

You can, but it returns until the camshaft sensor or its circuit is repaired.

Read & clear P0393 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