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OBD-II Code

P0347

Severity

Not yet reviewed

Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.

Can you drive it

We cannot say

Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.

Indicative cost (USD)

$60–$320

From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.

P0347 means the Bank 2 CMP A signal voltage has dropped below the ECM's low threshold (typically under 0.2V on a 5V Hall-effect circuit, or essentially flatline on a VR sensor), which the PCM reads as either a shorted-to-ground signal wire or a dead sensor.

How a shop works this

Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.

  1. Note every code that is set, not just this one.

    Codes that appear together usually narrow the cause faster than any one of them read alone.

  2. Read the freeze frame — the conditions the fault was recorded under.

    Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.

  3. Confirm the fault is current rather than history.

    Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.

  4. Then follow the diagnostic notes further down this page, in the order they are written.

    They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.

If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.

Common symptoms

  • Check engine light
Read the full diagnostic procedureP0347 means the Bank 2 CMP A signal voltage has dropped below the ECM's low threshold (typically under 0.2V on a 5V Hall-effect circuit, or essential…

P0347 means the Bank 2 CMP A signal voltage has dropped below the ECM's low threshold (typically under 0.2V on a 5V Hall-effect circuit, or essentially flatline on a VR sensor), which the PCM reads as either a shorted-to-ground signal wire or a dead sensor.

Cheapest-first ladder

  1. unplug the Bank 2 CMP connector with key-on, engine-off, and backprobe the signal pin - it should snap up to the 5V reference.
  2. If it does, the sensor is internally shorted or the reluctor air gap is wrong; install a new sensor and verify air gap to spec (typical 0.020 to 0.050 inch).
  3. If the signal wire stays near 0V with the connector unplugged, the wire is shorted to ground between the sensor and the PCM - backprobe at the PCM connector to localize the short.
  4. Verify the 5V reference at the sensor connector reads 4.9 to 5.1V key-on.
  5. Check the sensor ground pin for under 0.1 ohm continuity to PCM ground.
  6. On Hall-effect CMPs the healthy live signal toggles 0 to 5V square wave at cranking and idle; on VR sensors the signal swings from ~0.5V peak-to-peak at cranking up to 3 to 8V at idle.
  7. The expensive misdiagnosis is replacing the CMP sensor when the real fault is coolant or oil intrusion into the connector shorting the signal wire to the shield - dry, clean, and dielectric-grease the connector before condemning the sensor or a chasing a PCM driver.
Vehicle-specific patterns2007-2014 Ford 3.5L Cyclone V6 (Edge, Flex, Taurus, F-150 EcoBoost) gets coolant intrusion into the Bank 2 CMP harness from a leaking rear cylinder-h…
  • 2007-2014Ford 3.5L Cyclone V6 (Edge, Flex, Taurus, F-150 EcoBoost) gets coolant intrusion into the Bank 2 CMP harness from a leaking rear cylinder-head plug, shorting the signal to ground.
  • 2010-2016Hyundai/Kia 3.3/3.8 Lambda V6 sees the Bank 2 CMP pigtail chafe against the engine lift bracket, shorting the signal wire after 80k miles.
  • 2008-2013GM 3.6L LY7/LFX has known TSB coverage for Bank 2 CMP signal-wire corrosion at the under-intake splice pack.
  • 2007-2013Nissan VQ35DE/VQ40DE Bank 2 CMP can fail internally shorted after valve cover gasket oil intrusion saturates the sensor body.
  • 2011-2018Chrysler 3.6L Pentastar Bank 2 CMP fails internally shorted in batches - check for a TSB-covered updated sensor revision before throwing parts at it.

Estimated repair$60 to $320.

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