P0397
UniversalCamshaft Position Sensor 'B' Circuit Intermittent/Erratic (Bank 2)
Medium SeverityThis code indicates that the engine's computer (PCM) has detected an intermittent or erratic signal from the Camshaft Position Sensor B on Bank 2 of the engine. An unreliable signal from this sensor can disrupt the precise timing of fuel injection and ignition, leading to various engine performance issues.
⚠️ Before You Begin (Safety First)
Always ensure the engine is off and cool before attempting any repairs. Disconnect the battery's negative terminal to prevent accidental short circuits or electrical shocks. Be cautious of hot engine components and rotating parts.
Common Symptoms
- Check Engine Light illuminated
- Rough idle
- Poor engine performance
- Engine misfires
- Difficulty starting
- Engine stalling
- Reduced fuel economy
Common Causes
- Faulty Camshaft Position Sensor B (Bank 2)
- Damaged or corroded wiring harness leading to the sensor
- Poor electrical connection at the sensor connector
- Faulty reluctor ring/tone wheel on the camshaft (less common)
- Problem with the Powertrain Control Module (PCM) (rare)
Frequently reported on: 2008 Honda Pilot (3.5L V6), 2010 Nissan Altima (3.5L V6), 2007 Chevrolet Silverado (5.3L V8), 2009 Toyota Camry (3.5L V6), 2012 Dodge Ram 1500 (5.7L V8)
Diagnostic Steps
- Connect an OBD-II scanner to confirm the P0397 code and check for any other related codes.
- Visually inspect the wiring harness and electrical connector for the Camshaft Position Sensor B (Bank 2) for any signs of damage, fraying, corrosion, or loose connections.
- If accessible, test the resistance of the camshaft position sensor using a multimeter and compare it to manufacturer specifications (consult a service manual).
- If the sensor is suspected to be faulty based on inspection or testing, carefully remove and replace the Camshaft Position Sensor B (Bank 2).
- Clear the diagnostic trouble code (DTC) using the OBD-II scanner and perform a test drive to ensure the repair has resolved the issue and the code does not return.
👨🔧 When to Call a Professional
If symptoms persist after replacing the Camshaft Position Sensor B and inspecting the wiring, or if you are not comfortable performing electrical diagnostics, it's best to consult a professional technician. Complex wiring issues or an internal PCM fault can be difficult to diagnose without specialized tools.
Commonly Asked Questions
What does 'Bank 2' mean for this code?
Bank 2 refers to the side of the engine that does not contain cylinder number one. In V-type or Boxer engines, there are two cylinder banks.
Can I drive my vehicle with a P0397 code?
It is not recommended to drive with this code for an extended period, as it can cause engine stalling, poor performance, and potentially lead to more serious damage if engine timing is severely affected.
How do I locate the Camshaft Position Sensor B on Bank 2?
The exact location varies by vehicle make, model, and engine type. You should consult your vehicle's service manual or an online repair database specific to your car for its precise location.
Is it possible for wiring issues to cause P0397, even if the sensor is new?
Yes, wiring harness damage (like frayed wires, shorts, or opens) or a corroded/loose electrical connector are common causes of intermittent/erratic signals and should always be thoroughly inspected.
What if replacing the sensor doesn't fix the P0397 code?
If the code persists after sensor replacement, the issue could be with the wiring harness, the reluctor wheel (tone wheel) on the camshaft, or, rarely, a fault within the Powertrain Control Module (PCM).