FixItFor.Us
P codepowertrainMedium severity

P0366Camshaft Position Sensor "B" Circuit Range/Performance (Bank 1)

The bank 1 "B" camshaft position sensor signal is present but implausible — the pulse pattern or timing does not match what the PCM expects.

Definition

The PCM continuously compares the bank 1 "B" (typically exhaust) camshaft position signal against the crankshaft position signal for the correct number of pulses and correct alignment. P0366 sets when the signal exists but is erratic, noisy, or out of the expected window — a rationality failure rather than a dead circuit. Symptoms include hard or extended cranking, rough idle, reduced power, disabled variable valve timing on that cam, and a MIL; because the signal is only intermittently wrong, this code often points to mechanical timing or reluctor problems rather than a completely failed sensor.

Common causes

  • Stretched timing chain or worn guides skewing cam-to-crank correlation
  • Failing camshaft position sensor producing a noisy or dropout-prone signal
  • Damaged, loose, or debris-fouled cam reluctor/tone ring
  • Intermittent wiring fault or chafed harness inducing signal noise
  • Stuck or slow VVT phaser holding the cam out of its expected position
  • Low oil level/pressure or wrong viscosity affecting phaser response

Common misdiagnoses

  • Cam sensor replaced when the timing chain is stretched
  • VVT solenoid replaced when the reluctor or sensor signal is the problem
  • Timing chain replaced when a failing sensor is dropping pulses
  • PCM replaced for what is a mechanical correlation issue

Troubleshooting steps

  1. 1.Check for companion codes

    Correlation codes such as P0017 alongside P0366 shift suspicion strongly toward the timing chain or phaser rather than the sensor circuit.

  2. 2.Check oil level and condition

    Low, dirty, or wrong-viscosity oil disturbs VVT phaser behavior and is the cheapest fault to rule out first.

  3. 3.Scope cam and crank signals together

    Capture both waveforms at idle and snap throttle; look for dropped or extra cam pulses and drift in cam-to-crank alignment.

  4. 4.Inspect the sensor tip and reluctor

    Remove the sensor and check for metal shavings on its magnetic tip and for damage or runout on the tone ring.

  5. 5.Measure timing chain stretch

    Compare cam/crank correlation degrees on the scan tool or physically verify timing marks; replace the chain and guides if out of spec.

  6. 6.Test the VVT phaser

    Command the cam phaser through the scan tool and verify the measured cam position follows the commanded angle promptly.

Related codes