P0391 Code - Camshaft Position Sensor 'B' Circuit Range/Performance Bank 2
Quick Answer
The Camshaft Position Sensor is an electronic device used in an engine to record the rate at which the camshaft is spinning. Common causes include Faulty Camshaft Position Sensor, Camshaft Position Sensor harness is open or shorted, Camshaft Position Sensor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0391 indicates Camshaft Position Sensor 'B' Circuit Range/Performance Bank 2.
- Common causes
- Common causes include Faulty Camshaft Position Sensor, Camshaft Position Sensor harness is open or shorted, Camshaft Position Sensor circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P0391 Description
When the engine is running, the high and low parts of the teeth cause the gap with the sensor to change. The changing gap causes the magnetic field near the sensor to change. The change in the magnetic field cause the voltage from the sensor to change.
When the crankshaft position sensor (POS) system becomes inoperative, the camshaft position sensor provides various controls of engine parts instead, utilizing timing of cylinder identification signals.
What are the Possible Causes of the DTC P0391?
- Faulty Camshaft Position Sensor
- Camshaft Position Sensor harness is open or shorted
- Camshaft Position Sensor circuit poor electrical connection
- Faulty starter motor
- Starting system circuit
- Dead (Weak) battery
How to Fix the DTC P0391?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0391 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
Need more information about the P0391 code?
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Information for Specific Makes
- P0391 Audi — Camshaft Position Sensor 'B' Circuit Range/Performance Bank 2
- P0391 Hyundai — Camshaft Position Sensor 'B' Circuit Range/Performance Bank 2
- P0391 KIA — Camshaft Position Sensor 'B' Circuit Range/Performance Bank 2
- P0391 Volkswagen — Camshaft Position Sensor 'B' Circuit Range/Performance Bank 2
Frequently Asked Questions about P0391 Code
1. What are the common symptoms of OBDII code P0391 (Camshaft Position Sensor 'B' Circuit Range/Performance Bank 2)?
- Common symptoms include engine misfires, rough idling, poor acceleration, and potentially stalling while driving.
2. What are the possible causes of OBDII code P0391?
- The code P0391 can be triggered by a faulty camshaft position sensor, wiring issues in the sensor circuit, or problems with the engine control module (ECM).
3. How can I diagnose the cause of OBDII code P0391?
- Diagnosing the code typically involves checking the camshaft position sensor for proper operation, inspecting the sensor wiring for damage, and testing the ECM for any faults.
4. Can a dirty camshaft position sensor cause code P0391?
- Yes, a dirty or contaminated camshaft position sensor can lead to erratic readings and trigger code P0391. Cleaning or replacing the sensor may resolve the issue.
5. Is it safe to drive with OBDII code P0391 active?
- It is not recommended to drive with code P0391 active, as it can lead to engine performance issues and potential breakdowns. It's best to address the problem promptly.
6. How can I repair OBDII code P0391?
- Repairing code P0391 may involve replacing the camshaft position sensor, repairing any damaged wiring, or reprogramming the ECM to resolve the circuit range/performance issue.
7. Can a DIY enthusiast fix OBDII code P0391 at home?
- Depending on your experience and tools, some DIY enthusiasts may be able to diagnose and repair code P0391 at home. However, professional assistance may be needed for complex issues.
8. Will resetting the OBDII code P0391 clear the problem?
- Resetting the code may temporarily clear the check engine light, but if the underlying issue causing code P0391 is not addressed, the problem is likely to reoccur.
9. How long does it typically take to repair OBDII code P0391?
- The repair time for code P0391 can vary depending on the cause and complexity of the issue. It may take anywhere from 1 to 4 hours to diagnose and fix the problem.
10. Can OBDII code P0391 affect fuel efficiency?
- Yes, code P0391 can impact fuel efficiency due to engine performance issues. Resolving the code promptly can help improve fuel economy.
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