What does P0394 mean?

AutoFixDB - Free OBD-II diagnostic trouble code lookup. Find causes, symptoms, diagnostic steps and repair solutions.

Overview

P0394 generic OBD-II code indicating intermittent fault in camshaft position sensor B circuit on engine bank 2, intermittent signal loss often electrical in nature affecting timing and injector synchronization

Common Symptoms

Check Engine Light illuminated
Intermittent rough idle or engine bucking
Hesitation or loss of power under acceleration
Intermittent engine stalling
Misfire-like symptoms

Most Common Causes

Intermittent open or short in camshaft position sensor B wiring or connector high

Loose connector, chafed wiring, or intermittent shorts frequently cause this code

Faulty camshaft position sensor B medium

Sensor internal failure or aging can produce intermittent signals

Corroded or poor electrical ground/power supply to sensor medium

Voltage irregularities may trigger intermittent code

Tone ring damage or contamination at sensor low

Mechanical damage or oil contamination affecting sensor reading

ECM/PCM input circuit fault low

Rare internal controller faults may misinterpret valid signal as intermittent

Diagnostic Steps

Connect OBD-II scan tool and confirm P0394 and any related codes

Expected: P0394 confirmed, note any additional camshaft or crankshaft sensor codes

Interpretation: Code presence confirms intermittent camshaft sensor B circuit issue
Visually inspect wiring harness and connector for sensor B

Expected: No broken wires, corrosion, or loose connector

Interpretation: Damaged or corroded wiring suggests electrical fault
Perform wiggle test on wiring while engine is idling

Expected: No change in engine behavior or code set

Interpretation: Intermittent connection may show changes during wiggle
Check sensor reference voltage (typically ~5V) and ground with multimeter

Expected: Stable 5V supply and good ground

Interpretation: Voltage anomalies indicate supply or ground problem
Test sensor signal output with scan tool or scope

Expected: Consistent pulse signal appropriate for cam speed

Interpretation: Intermittent or missing signal indicates sensor or tone ring issue

Repair Solutions

Repair or replace damaged wiring and connectors medium

Estimated Cost: $50 - $200

Fixing harness issues often resolves intermittent faults

Replace camshaft position sensor B medium

Estimated Cost: $100 - $300

Use OEM or high quality sensor for reliability

Clean or replace tone ring if damaged hard

Estimated Cost: $150 - $500

May require deeper engine access and timing cover removal

Repair or reprogram ECM/PCM if internal fault confirmed hard

Estimated Cost: $300 - $1200

Rare; only after all other diagnostics rule out external faults

Common Misdiagnoses

Avoid these common diagnostic mistakes:

Incorrectly attributing symptoms to fuel system or ignition coil issues without checking camshaft sensor circuit

Frequently Asked Questions

Technical definition of P0394 OBD-II Code

When your OBD-II scanner reads P0394, it means: Camshaft Position Sensor "B" Circuit Intermittent (Bank 2). This code is related to the vehicle's Sensors.

How serious is the P0394 code?

The P0394 code is considered medium severity. Intermittent engine performance issues including rough idle, hesitation, or potential stalling due to intermittent camshaft position signal loss

Symptoms associated with DTC P0394

You may experience the following: Check Engine Light illuminated, Intermittent rough idle or engine bucking, Hesitation or loss of power under acceleration.

What parts fail when P0394 is set?

The most common causes are: Intermittent open or short in camshaft position sensor B wiring or connector, Faulty camshaft position sensor B, Corroded or poor electrical ground/power supply to sensor.

Estimated repair costs for different causes of P0394

It depends on what needs to be fixed. Repair or replace damaged wiring and connectors repairs are cheaper (~$200), while Repair or reprogram ECM/PCM if internal fault confirmed repairs are on the higher end (~$1200).

Does P0394 affect Ford, Toyota, or Honda?

P0394 is not specific to any one brand. It can appear on Ford, Dodge, Toyota, Honda, Jeep, and other vehicles.

P0394: Camshaft Position Sensor "B" Circuit Intermittent (Bank 2)