What Does P0366 Mean?
The camshaft position sensor B on bank 1 is providing a signal that falls outside the expected range or is not performing correctly relative to the crankshaft position sensor. On DOHC engines, this indicates the exhaust camshaft timing relationship is off or the sensor B signal quality is degraded. The driver may notice hard starting, rough idle, reduced power, and poor fuel economy.
Common Causes
30%
Exhaust camshaft VVT actuator/phaser stuck or malfunctioning, holding the exhaust cam out of expected position
25%
Stretched timing chain on the exhaust camshaft drive causing phase deviation beyond tolerance
20%
Degraded CMP sensor B producing weak or distorted signal waveform
15%
Damaged exhaust camshaft reluctor ring with worn or chipped teeth altering signal pattern
10%
Low or degraded engine oil affecting VVT actuator response and timing chain tension
Diagnostic Steps
1
Monitor exhaust camshaft target vs. actual advance angles on live data — deviation of more than 5-10 degrees from the commanded position indicates a VVT actuator or timing chain issue.
2
Capture CKP and CMP B waveforms simultaneously on an oscilloscope — compare the phase relationship to the expected pattern for the engine to determine if the exhaust cam timing has shifted.
3
Check engine oil level and condition — low oil or sludged oil is the number one cause of VVT actuator malfunction; ensure oil is at the correct level and meets manufacturer viscosity specification.
4
Command the exhaust VVT solenoid through its full range using bi-directional controls and monitor the CMP B response — a sluggish or non-responsive actuator confirms a VVT system fault.
5
Listen for timing chain rattle on cold start — worn chains and tensioners will rattle for a few seconds before oil pressure builds and the tensioner takes up slack.
Estimated Repair Cost
$150 - $1,200
Parts + labor, varies by vehicle and location
The camshaft position sensor B on bank 1 is providing a signal that falls outside the expected range or is not performing correctly relative to the crankshaft position sensor. On DOHC engines, this indicates the exhaust camshaft timing relationship is off or the sensor B signal quality is degraded. ...
The most common cause of P0366 (Camshaft Position Sensor "B" Circuit Range/Performance (Bank 1)) is: Exhaust camshaft VVT actuator/phaser stuck or malfunctioning, holding the exhaust cam out of expected position
Typical repair costs for P0366 range from $150 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Drivable with reduced performance but have the issue diagnosed soon. A stretched timing chain can worsen over time and eventually jump teeth, which on interference engines can cause catastrophic valve-to-piston contact. If engine noise increases or misfires become more frequent, stop driving immediately.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0366 to identify the root cause.
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Quick Info
Category
Powertrain
System
Engine Timing / Variable Valve Timing
Difficulty
Type
Generic (SAE)
Recommended Tools
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