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P0347Camshaft Position Sensor "A" Circuit Low (Bank 2)

The bank 2 camshaft position sensor "A" circuit is stuck at a low voltage with no valid signal.

Definition

The camshaft position sensor on bank 2 (typically a hall-effect sensor fed with a 5 V or 12 V supply) should produce a switching square-wave signal as the cam reluctor passes; P0347 sets when the PCM sees the signal circuit held low, indicating a short to ground, a dead sensor, or a missing supply voltage. Depending on the strategy, the engine may still start and run on the crankshaft sensor in a fallback mode, but expect long crank times, possible stalling or a no-start, loss of sequential injection and bank 2 VVT control, reduced power, and an illuminated MIL.

Common causes

  • Failed camshaft position sensor
  • Signal wire shorted to ground (chafed harness, pinched at a bracket or cover)
  • Missing sensor supply voltage (open feed wire or blown circuit feeding the sensor)
  • Corroded or oil-fouled connector terminals
  • PCM input circuit fault (rare)

Common misdiagnoses

  • Replacing the crankshaft position sensor
  • Replacing the sensor without finding the harness short that killed the signal
  • Replacing the PCM
  • Condemning the timing chain when the fault is purely electrical

Troubleshooting steps

  1. 1.Verify power and ground at the sensor connector

    Key on, confirm the supply pin reads spec (5 V or ~12 V depending on design) and the ground pin drops less than 0.1 V to battery negative.

  2. 2.Check the signal circuit bias

    With the connector on, backprobe the signal wire key-on; many hall sensors rest at a pull-up voltage — a constant 0 V indicates a grounded circuit or dead sensor.

  3. 3.Isolate sensor versus harness

    Unplug the sensor; if the signal wire's pull-up voltage returns, replace the sensor, and if it stays at 0 V, find the harness short to ground.

  4. 4.Scope the signal while cranking

    A healthy sensor shows a clean square wave during cranking; a flatline at 0 V with verified power and ground condemns the sensor.

  5. 5.Inspect for oil intrusion and physical damage

    Check for oil wicking into the connector from a leaking sensor O-ring and for a damaged reluctor if the sensor tip shows contact marks.

  6. 6.Clear codes and verify starting behavior

    Confirm normal crank time and no code reset over several cold and hot starts.

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