P0366 means Camshaft Position Sensor B Circuit Range/Performance (Bank 1). The signal from camshaft sensor B on bank 1 (usually the exhaust camshaft) is present but erratic, or does not line up with the crankshaft signal as expected. It is a generic OBD-II code, so the definition is the same on any make, but the most likely cause varies by engine; confirm with a scan tool and the service information for your vehicle before buying parts.
What P0366 means
The engine computer uses the crankshaft position sensor to know engine speed and piston position, and the camshaft sensors to know which stroke each cylinder is on. On engines with variable valve timing, oil-driven cam phasers rotate the camshafts relative to the crankshaft under the control of solenoids. Timing codes come from a sensor that cannot be read, or from a measured cam angle that does not match the commanded one, so oil level and condition, sensor signals and mechanical timing all need checking.
P0366 symptoms
- Hard starting
- Rough running
- Check engine light, sometimes with cam timing codes
Common causes of P0366
- Timing chain stretch or cam phaser problems
- Damaged reluctor
- Intermittent wiring or an oil-soaked connector
- Failing sensor
How to diagnose P0366
- Check oil level and condition, and confirm the oil viscosity matches the specification
- Check for related timing codes
- Scope the cam and crank signals together
- Inspect the connector for oil from a leaking cover gasket
Can you drive with P0366?
Usually drivable in the short term; repair soon.
P0366 tips
Exhaust cam sensors sit near hot parts and leaking valve cover gaskets, so oil-soaked or heat-damaged connectors are common. Fix the leak when replacing the sensor.
Will P0366 clear itself?
If the fault stops, the computer turns off the check engine light by itself after several drive cycles without seeing it again, and the code stays in memory as history for a while. Clearing P0366 with a scan tool after a repair is fine, but if the cause is still there the code returns, sometimes within one drive. Disconnecting the battery also clears codes on most vehicles, but it erases learned fuel trims and idle settings as well.
Related codes
| Code | Meaning |
|---|---|
| P0365 | Camshaft Position Sensor B Circuit (Bank 1) |
| P0017 | Crankshaft Position – Camshaft Position Correlation (Bank 1 Sensor B) |
| P0014 | Exhaust Camshaft Position Timing Over-Advanced or System Performance (Bank 1) |
Guides that help
When it is more than a sensor
If a stretched chain has already jumped time and damaged valves, or low oil pressure has worn the engine, a repair can cost more than a replacement; see engine replacement cost and compare engines by code on our engines page.
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