P0394: Camshaft Position Sensor B Circuit Intermittent Bank 2

Camshaft position sensor B is the exhaust camshaft sensor; bank 2 is the side without cylinder 1, so the code only occurs on V and boxer engines with one exhaust cam sensor per bank. P0394 means the bank 2 exhaust cam signal now and then appears at a position where it is not expected relative to the crank reference – sporadic extra or missing edges. Ford checks this in its camshaft ignition system test from 200 rpm and decides within 5 s. FCA also uses the code and asks dealers to save the cam/crank synchronisation event data before replacing parts, a hint that the sensor itself is often not the culprit. GM does not use P0394 and reports such faults under P0391. Typical causes are a loose contact, interference or a damaged tone wheel.

Bank 2 is the side without cylinder 1, so it only exists on V or boxer engines.

Symptoms

• Check engine light on
• Sporadic jerking or stalling
• Occasionally longer cranking

Most likely causes

• Loose contact or corrosion at the sensor connector or harness
• Interference (ignition wiring, add-on devices, ground problems)
• Tone wheel or phaser damaged, or sensor loose
• Sensor faulty, temperature-dependent

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the connector and look for metal filings on the sensor
2. Gently move the wiring with the engine running and watch whether the reading changes.
3. See whether there is an RPM signal while cranking
4. Measure the signal with an oscilloscope if you can
5. Check the engine timing before replacing expensive parts

Good to know

• Repair difficulty: medium
• It can trigger limp mode.
• It affects emissions.

What each character of P0394 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 3: Ignition and misfires
• 94: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0394?

Avoid driving: the engine can stall while moving. If the timing is off, continuing can cause serious damage.

What causes code P0394?

The most common causes are: loose contact or corrosion at the sensor connector or harness; interference (ignition wiring, add-on devices, ground problems); tone wheel or phaser damaged, or sensor loose.

Related codes

• P0390Camshaft Position Sensor B Circuit Bank 2
• P0391Camshaft Position Sensor B Circuit Range/Performance Bank 2
• P0369Camshaft Position Sensor B Circuit Intermittent Bank 1
• P0349Camshaft Position Sensor A Circuit Intermittent Bank 2
• P0018Crankshaft Position - Camshaft Position Correlation (Bank 2 Sensor A)

Sources

• newtonnet.co.uk: fordobd2012
• fordservicecontent.com: OBD Operations Summary Gasoline 2020 2023
• static.nhtsa.gov: MC 10149004 9999
• law.cornell.edu: 13 CCR 1968.2

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.