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P codepowertrainMedium severity

P0368Camshaft Position Sensor "B" Circuit High (Bank 1)

The bank 1 "B" camshaft position sensor circuit is stuck at a high voltage, indicating a short to power or an open signal circuit.

Definition

The bank 1 "B" (typically exhaust) camshaft position sensor output should toggle between high and low as the cam reluctor teeth pass the sensor. P0368 sets when the PCM sees the signal circuit fixed above the maximum expected voltage — commonly a signal wire shorted to battery or reference voltage, an open circuit letting an internal pull-up hold the line high, or a failed sensor. Symptoms mirror other cam sensor "B" circuit faults: MIL illumination, possible hard starting or extended cranking, rough running, and disabled variable valve timing on that camshaft.

Common causes

  • Signal wire shorted to battery voltage or the 5 V reference
  • Open circuit in the signal or ground wire (pull-up holds line high)
  • Failed camshaft position sensor with output stuck high
  • Corroded or backed-out connector terminal creating an open
  • PCM input circuit fault (least common)

Common misdiagnoses

  • Sensor replaced when the fault is an open or shorted harness
  • Timing chain or VVT parts replaced for an electrical circuit code
  • PCM replaced before checking for a backed-out connector terminal
  • Battery/charging system serviced for an unrelated stuck-high signal

Troubleshooting steps

  1. 1.Read the signal voltage key-on

    A signal pinned at battery voltage suggests a short to power; pinned at the bias/pull-up voltage with no toggling while cranking suggests an open or dead sensor.

  2. 2.Inspect the connector terminals

    Check for backed-out, spread, or corroded pins on both the sensor and PCM sides — a common cause of an open signal circuit.

  3. 3.Check circuit continuity

    With both ends disconnected, verify low resistance (under 1 ohm) on signal, supply, and ground wires end to end, and no continuity between the signal wire and power feeds.

  4. 4.Substitute a known-good sensor

    If wiring checks pass, install a quality replacement sensor and scope for a toggling square wave while cranking.

  5. 5.Verify the repair over drive cycles

    Confirm the code does not return through several warm-up cycles, since opens are often thermally intermittent.

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