P0393
Fix within a few daysCamshaft Position Sensor 'B' Circuit High (Bank 2)
Code P0393 means your engine's Bank 2 Camshaft Position Sensor 'B' circuit has a high voltage signal. Common causes: Faulty sensor (70%), wiring issues (20%). Drivability: Yes, for short trips only. Repair cost: $30-$150 DIY, $150-$400 professional.
Can I Drive With P0393?
Yes, for short trips only
Essential trips under 10 miles, avoid highways and heavy acceleration
Stop driving immediately if: Flashing Check Engine Light, engine stalls repeatedly, significant power loss, or loud engine noises.
Symptoms of P0393
- 1Check Engine Light is on
- 2Engine is hard to start or cranks for a long time
- 3Engine stalls frequently
- 4Rough idle or engine runs poorly
- 5Reduced engine power or acceleration
- 6Poor fuel economy
Common Causes of P0393
Parts most likely causing this code, ranked by probability
The sensor itself has failed internally, sending an incorrect high voltage signal to the engine computer.
70% of P0393 cases are fixed by replacing this part
Damaged, corroded, or loose wiring or connector pins create an open circuit or high resistance, causing a high voltage reading.
20% of P0393 cases are fixed by repairing wiring or connector
If the timing chain or belt is stretched or misaligned, the camshaft position signal can be erratic or out of range, triggering the code.
5% of P0393 cases are fixed by addressing timing component issues
A rare internal fault within the engine computer's input circuit for the camshaft position sensor can cause this code.
5% of P0393 cases are fixed by replacing the ECM/PCM
Check These First (Before Buying Parts)
- Visually inspect the electrical connector at the camshaft position sensor for any looseness, corrosion, or damaged pins.
- Examine the wiring harness leading to the sensor for any visible signs of cuts, fraying, or rodent damage.
How to Diagnose P0393
- 1Visually inspect the camshaft position sensor 'B' (Bank 2) and its electrical connector for any obvious damage, corrosion, or loose connections.
- 2Check the wiring harness leading to the sensor for any signs of fraying, cuts, or heat damage.
- 3Using an OBD-II scan tool, check for any other related diagnostic trouble codes (DTCs) that might point to a broader issue.
- 4With a multimeter, test the voltage and resistance of the camshaft position sensor and its circuit according to your vehicle's service manual specifications.
- 5If the sensor and wiring check out, use a scan tool with live data to monitor the camshaft position sensor signal while cranking or running the engine to check for erratic readings.
- 6If all electrical checks pass, consider inspecting engine timing components if symptoms persist and other codes suggest timing issues.
P0393 on Popular Vehicles
Toyota Camry
2007-2024Camry models frequently experience camshaft position sensor failures around 100,000 to 150,000 miles. The sensor itself is a common failure point.
75% fixed by replacing the sensor
Honda Accord
2003-2024Honda Accord engines can also develop P0393 due to a failing camshaft position sensor. Wiring integrity should always be checked, as Honda harnesses can be susceptible to wear.
70% fixed by replacing the sensor
Ford F-150
2004-2024On Ford F-150s with V8 engines, P0393 typically points to the exhaust camshaft position sensor on Bank 2. Access can sometimes be challenging depending on the engine configuration.
80% fixed by replacing the sensor
Frequently Asked Questions
What does P0393 mean?
P0393 indicates that your vehicle's engine computer (ECM/PCM) has detected a high voltage signal from the Camshaft Position Sensor 'B' on Bank 2. This sensor is crucial for monitoring the camshaft's rotation and position, which the computer uses to control fuel injection and ignition timing.
Can I drive with P0393?
Yes, for short trips only. You can drive your vehicle for essential, short trips, but you should fix this code within a few days. Ignoring it can lead to stalling, hard starting, reduced power, and poor fuel economy. Continued driving with incorrect timing signals can stress other engine components.
Will P0393 clear itself?
No, P0393 will not clear itself. The Check Engine Light will remain on until the underlying issue causing the high voltage signal from the camshaft position sensor is diagnosed and repaired. After the repair, you will need to clear the code with an OBD-II scan tool.
How do I fix P0393 myself?
Start by visually inspecting the camshaft position sensor 'B' (Bank 2) and its wiring for damage or corrosion. If the wiring looks good, replace the camshaft position sensor. This is often a straightforward bolt-on replacement. After replacement, clear the code with a scan tool.
How much does it cost to fix P0393?
The cost to fix P0393 yourself is typically $30-$150 for the camshaft position sensor part. If you take it to a professional shop, expect to pay $150-$400, which includes the part and 1-2 hours of labor.
P0393 keeps coming back - why?
If P0393 keeps returning, it means the initial repair did not address the root cause. Common reasons include a faulty replacement sensor, an undiagnosed wiring issue (such as a short or open circuit), a problem with the engine's timing components, or, in rare cases, a failing engine computer.
Will P0393 fail emissions/smog test?
Yes, P0393 will cause your vehicle to fail an emissions or smog test. A Check Engine Light illuminated for any reason, including P0393, is an automatic failure in states with emissions testing. The code indicates an issue that affects engine efficiency and potentially emissions.
What's the difference between P0393 and P0340?
P0393 refers to a high circuit signal from Camshaft Position Sensor 'B' on Bank 2. P0340 refers to a circuit malfunction for Camshaft Position Sensor 'A' on Bank 1. 'Bank 1' is the side of the engine with cylinder #1, and 'Bank 2' is the opposite side. 'Sensor A' is typically the intake camshaft, and 'Sensor B' is the exhaust camshaft.
P0393 on Ford F-150?
On Ford F-150s, especially those with V8 engines, P0393 is often caused by a failing exhaust camshaft position sensor on Bank 2. These sensors can degrade over time, leading to erratic signals. Always check the wiring harness for rodent damage, which is also common on trucks.
Questions to Ask Your Mechanic
Did you test the voltage and resistance of the camshaft position sensor and its circuit?
Good answer: Yes, I confirmed the sensor's output voltage was consistently high and out of specification, and the wiring showed no signs of shorts or opens.
What did you find when inspecting the wiring harness to the sensor?
Good answer: I thoroughly checked the wiring from the sensor back to the ECM for any damage, corrosion, or loose connections and found no issues.
Repair Cost Estimate
DIY Repair
Parts only
$30-$150
Shop Repair
Parts + labor
$150-$400
Save $120-$250 by doing it yourself
Difficulty
intermediate
Time
1-2 hours
Intermediate - requires basic hand tools, an OBD-II scan tool to clear codes, and a multimeter for proper diagnosis. Access to the sensor can vary by vehicle.
Cost of Waiting
Ignoring P0393 can lead to stalling, hard starting, and reduced engine performance. Continued driving with incorrect timing signals can put stress on other engine components and potentially lead to catalytic converter damage if misfires occur, turning a $100 sensor job into a $1,200-$2,500 repair.
While You're In There...
Applying dielectric grease to the electrical connector pins helps prevent corrosion and ensures a good electrical connection, which is critical for sensor signals.
Tools You'll Need
- Basic hand tools (sockets, wrenches)
- OBD-II scan tool
- Multimeter
- Wire brush (for cleaning connectors)
P0393 is a common sensor code. Most repairs involve replacing the camshaft position sensor, which is a straightforward job for an intermediate DIYer, and your engine will run smoothly afterward.
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Your Next Steps
Step 1: Visually inspect the camshaft position sensor 'B' (Bank 2) connector and wiring for any obvious damage or corrosion. Clean any corrosion you find.
Step 2: If the visual inspection doesn't reveal any issues, use a multimeter to test the sensor's resistance and voltage output according to your vehicle's service manual. If it's out of spec, replace the sensor.
Step 3: If the sensor tests good, but the code persists, carefully inspect the entire wiring harness from the sensor back to the engine computer for any breaks or shorts. You'll likely need a new camshaft position sensor.