Powertrain, generic · Ignition system or misfire

P0394 Camshaft Position Sensor B Circuit Intermittent Bank 2

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

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.

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

Symptoms

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

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–300
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

camshaft position sensor exhaustcamshaft tone wheelsensor wiringengine control module

Related codes

P0390P0391P0369P0349P0018

References: newtonnet.co.uk, fordservicecontent.com, static.nhtsa.gov, law.cornell.edu.