P0347
Camshaft Position Sensor A Circuit Low Input (Bank 2)P0347 is a generic OBD-II powertrain diagnostic trouble code: Camshaft Position Sensor A Circuit Low Input (Bank 2). It is logged by the engine control unit when the ckp/cmp monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What P0347 means
P0347 is stored when the PCM detects that the signal voltage from the Bank 2 Camshaft Position Sensor "A" has fallen below the minimum threshold required for a valid reading. Unlike P0346 (a rationality or range/performance fault where the signal is present but incorrect), P0347 is a hard electrical fault: the circuit is essentially dead — either the sensor has failed internally, the signal wire is shorted to ground, or the circuit is open.
The CMP sensor on Bank 2 typically operates as a Hall-effect device powered by a 5 V or 12 V reference from the PCM. When the toothed reluctor ring on the camshaft passes the sensor tip, the output switches between a low and high voltage. If the output is permanently stuck in the low state (typically below ~0.3 V on a 5 V reference circuit), the PCM cannot determine cam position and logs P0347. On most engines a fallback strategy allows the engine to continue running on crankshaft position data alone, but with degraded timing control.
Correct sensor-to-reluctor clearance is critical: the sensor should sit 0.5–1.3 mm (0.020"–0.050") from the tone ring. An incorrectly seated or cocked sensor produces a signal too weak to switch cleanly and can set a low-input code even with a functioning sensor. Oil leaks soaking the connector are another frequent culprit on high-mileage engines.
Common causes
Most-frequently reported root causes when P0347 is logged.
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1
Faulty Bank 2 CMP sensor "A" with internally shorted or open Hall-effect element
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2
Signal wire shorted to ground (damaged insulation contacting chassis or engine block)
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3
Open circuit in the signal wire between the sensor and the PCM (broken wire, corroded pin)
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4
Corroded or oil-saturated sensor connector reducing signal voltage below threshold
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5
Sensor incorrectly seated with excessive clearance to the reluctor ring, producing a sub-threshold signal
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6
Damaged or missing teeth on the Bank 2 camshaft tone ring
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7
Loss of 5 V reference voltage at the sensor connector (check reference supply fuse/circuit)
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8
PCM internal fault on the Bank 2 cam-input channel (diagnose last)
Symptoms drivers notice
How to diagnose P0347
A typical diagnostic flow when this code is present.
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1
Retrieve all DTCs and freeze-frame data; note whether accompanying misfire or crank-sensor codes are present
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2
Visually inspect the Bank 2 CMP sensor and its wiring harness for obvious damage, oil contamination, bent connector pins, and loose locks
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3
With ignition on (engine off), use a DVOM to check for reference voltage (typically 5 V) at the sensor connector power pin; absence indicates an upstream wiring or PCM supply fault
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4
Check the sensor ground pin for continuity to chassis ground (should read < 0.1 Ω); high resistance indicates an open ground circuit
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5
With the sensor disconnected, measure resistance across the signal wire to chassis ground — any reading other than infinite (open) indicates a short to ground in the harness
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6
Reinstall a known-good or new sensor and verify correct seating and gap; use a feeler gauge if accessible to confirm 0.5–1.3 mm clearance to the tone ring
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7
Start the engine and monitor live CMP sensor voltage on a scan tool; the signal should toggle cleanly between low and high states as the engine turns
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8
If signal remains flat-low with a new sensor, trace the signal wire back to the PCM for continuity and shorts before concluding the PCM is at fault
Related powertrain codes
- P000A — A Camshaft Position Slow Response Bank 1
- P000B — B Camshaft Position Slow Response Bank 1
- P000C — A Camshaft Position Slow Response Bank 2
- P000D — B Camshaft Position Slow Response Bank 2
- P0010 — A Camshaft Position Actuator Circuit (Bank 1)
- P0011 — A Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)
Frequently asked questions
Can P0347 cause a no-start condition?
Yes. While most PCMs can use crankshaft position data as a fallback, some calibrations require a valid cam signal for initial startup timing, especially on direct-injection or variable-valve-timing engines. A hard circuit-low fault on Bank 2 can prevent start or cause immediate stall after start.
How does P0347 differ from P0345?
P0345 is a general circuit fault for the Bank 2 CMP "A" sensor (signal absent or severely erratic), while P0347 specifically indicates the circuit voltage is stuck in the low state. P0347 provides a more precise electrical diagnosis — short to ground or open circuit — compared to the broader P0345.
What is the correct sensor gap, and does it matter?
Yes. Hall-effect CMP sensors require a clearance of approximately 0.5–1.3 mm (0.020"–0.050") to the reluctor ring. A sensor that is cocked, cross-threaded, or has a damaged mounting boss may sit too far from the ring, generating a signal too weak to cross the switching threshold, resulting in a false low-input code despite a functional sensor.
Is Bank 2 always the passenger side?
On most rear-wheel-drive American V8 engines (GM LS/LT, Ford Modular/Coyote) Bank 2 is the passenger side. However, orientation varies by manufacturer and engine installation angle — always confirm which physical bank is Bank 2 using a vehicle-specific repair manual or wiring diagram before replacing parts.
Disabling P0347 in software
RaceTune can permanently disable P0347 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.
Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.
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