P0390
Fix within a few daysThe engine computer isn't getting a proper signal from the Bank 2, Sensor B camshaft position sensor.
Code P0390 means the engine computer isn't getting a proper signal from the Bank 2, Sensor B camshaft position sensor. Common causes: Camshaft position sensor (75%), wiring/connector (20%). Drivability: Limit driving, fix within a few days. Repair cost: $70-$250 DIY, $150-$500 professional.
Can I Drive With P0390?
Limit driving, fix within a few days
Essential trips under 10 miles, avoid highways and heavy traffic. Be prepared for potential stalling.
Stop driving immediately if: Engine stalls repeatedly, won't start, or has significant power loss.
Symptoms of P0390
- 1Check Engine Light is on
- 2Engine is hard to start or won't start
- 3Engine stalls unexpectedly
- 4Engine runs rough or idles poorly
- 5Reduced engine power or acceleration
- 6Decreased fuel economy
Common Causes of P0390
Parts most likely causing this code, ranked by probability
The sensor itself has failed and is sending an incorrect or no signal to the engine computer.
75% of P0390 cases are fixed by replacing this part
Damaged, corroded, or loose wiring or connector pins prevent the sensor signal from reaching the engine computer.
20% of P0390 cases are fixed by repairing the wiring or connector
A rare internal fault in the engine computer prevents it from correctly processing the camshaft sensor signal.
5% of P0390 cases are fixed by replacing the ECM/PCM
Check These First (Before Buying Parts)
- Visually inspect the camshaft position sensor (Bank 2, Sensor B) connector and wiring for any obvious damage, corrosion, or loose connections. Ensure it's fully seated.
- Check your engine oil level and condition. Extremely low or dirty oil can sometimes affect VVT systems, which rely on oil pressure, though less directly related to a circuit malfunction code.
How to Diagnose P0390
- 1Visually inspect the camshaft position sensor (Bank 2, Sensor B) and its electrical connector for any signs of damage, corrosion, or loose connections.
- 2Check the wiring harness leading to the sensor for any frayed wires, cuts, or signs of rodent damage.
- 3Using a multimeter, test the sensor's resistance and voltage output according to your vehicle's service manual specifications.
- 4If available, use a scan tool with live data to monitor the camshaft position sensor signal while cranking or running the engine.
- 5If the sensor and wiring check out, consider testing the continuity of the wiring back to the ECM/PCM.
P0390 on Popular Vehicles
Honda Accord
2003-2024Honda V6 engines (like the J-series) are known to have camshaft position sensor failures. Access to Bank 2, Sensor B can sometimes be challenging depending on the engine layout.
70% fixed by replacing the camshaft position sensor
Ford F-150
2004-2024On Ford F-150s with V6 or V8 engines, P0390 often points to a faulty sensor. Wiring issues, especially near the sensor connector, are also common due to engine bay heat and vibration.
75% fixed by replacing the camshaft position sensor
Chevrolet Silverado
2007-2024Chevrolet Silverado trucks, particularly those with V8 engines, can experience P0390 due to sensor failure. It's important to confirm which bank is Bank 2 and which sensor is 'B' for your specific engine configuration.
70% fixed by replacing the camshaft position sensor
Frequently Asked Questions
What does P0390 mean?
P0390 indicates that the engine's computer has detected an issue with the electrical circuit for the camshaft position sensor on Bank 2, Sensor B. This sensor tells the computer the exact position of the camshaft.
Can I drive with P0390?
Limit driving, fix within a few days. If your engine is stalling, running very rough, or won't start, do not drive the vehicle. If it's just the Check Engine Light, you can drive for essential short trips, but get it fixed quickly to prevent further issues.
Will P0390 clear itself?
No, P0390 will not clear itself. The engine computer stores this code until the underlying issue is resolved and the system passes its self-test, or until the code is manually cleared with a scan tool.
How do I fix P0390 myself?
Start by inspecting the camshaft position sensor (Bank 2, Sensor B) and its wiring for visible damage or corrosion. If the wiring looks good, replacing the camshaft position sensor is the most common fix. Ensure you get the correct sensor for Bank 2, Sensor B.
How much does it cost to fix P0390?
DIY repair costs for P0390 typically range from $70 to $250 for a new camshaft position sensor. Professional repair at a shop usually costs between $150 and $500, including parts and labor.
P0390 keeps coming back - why?
If P0390 keeps returning, it often means the initial diagnosis missed something. Double-check the wiring harness for intermittent breaks, ensure the new sensor is a quality part, or consider that the issue might be with the crankshaft position sensor or, rarely, the ECM.
Will P0390 fail emissions/smog test?
Yes, P0390 will cause your vehicle to fail an emissions or smog test. The Check Engine Light being on automatically results in a failure in most states, and a faulty camshaft sensor can also affect engine performance and emissions.
What's the difference between P0390 and P0340?
P0390 specifically refers to a circuit malfunction with the Bank 2, Sensor B camshaft position sensor. P0340 is a more general code indicating a circuit malfunction for the Bank 1, Sensor A camshaft position sensor. They point to issues on different banks or different sensors on the same bank.
P0390 on Honda Accord
On Honda Accords, P0390 is frequently caused by a failing camshaft position sensor itself. These sensors can degrade over time. Always verify you are replacing the correct sensor (Bank 2, Sensor B) as some V6 engines have multiple camshaft sensors.
Questions to Ask Your Mechanic
Did you test the voltage and resistance of the Bank 2, Sensor B camshaft position sensor?
Good answer: Yes, I confirmed the sensor's readings are outside the manufacturer's specifications, indicating a faulty sensor.
Did you inspect the wiring harness and connector for the Bank 2, Sensor B camshaft position sensor for damage or corrosion?
Good answer: Yes, I thoroughly checked the wiring and connector and found no visible damage or corrosion. The circuit has good continuity.
Repair Cost Estimate
DIY Repair
Parts only
$70-$250
Shop Repair
Parts + labor
$150-$500
Save $80-$250 by doing it yourself
Difficulty
intermediate
Time
1-3 hours
Intermediate - requires basic hand tools and a multimeter for proper diagnosis. Access to the sensor can sometimes be challenging.
Cost of Waiting
Ignoring P0390 can lead to persistent hard starting, engine stalling in traffic, and reduced engine performance. This creates a safety hazard and can leave you stranded. Continued poor engine operation also reduces fuel economy.
While You're In There...
While less likely to be the direct cause of P0390, the crankshaft position sensor works in conjunction with the camshaft sensor. If you're experiencing intermittent issues, replacing both can prevent future related problems and often shares some diagnostic steps.
Proper engine oil pressure and cleanliness are crucial for camshaft timing systems. Ensuring fresh oil and a clean filter supports the overall health of components related to camshaft position sensing.
Tools You'll Need
- Basic hand tools (sockets, wrenches)
- Multimeter
- Wire stripper/crimper (if wiring repair is needed)
- Scan tool with live data (helpful for diagnosis)
P0390 is a common sensor code. Most repairs involve replacing a relatively inexpensive part, and your engine will run reliably again once fixed.
- Family-owned since 1957
- 990,000+ happy customers
- Fast nationwide shipping
- Easy returns
Your Next Steps
Step 1: Visually inspect the Bank 2, Sensor B camshaft position sensor and its electrical connector and wiring for any damage, corrosion, or loose connections. Wiggle the connector to see if the engine light flickers or changes behavior.
Step 2: If the visual inspection doesn't reveal an obvious issue, use a multimeter to test the sensor's resistance and voltage output. Compare your readings to the specifications in your vehicle's repair manual. If readings are off, replace the sensor.
Step 3: If the sensor tests good, carefully inspect the entire wiring harness from the sensor back to the ECM for continuity and shorts. If wiring is damaged, repair it. If all else checks out, a rare ECM issue might be present, requiring professional diagnosis.