OBD-II trouble code
P0347: Camshaft Position Sensor "A" Circuit Low (Bank 2)
SAE J2012: Camshaft Position Sensor "A" Circuit Low (Bank 2). The signal sits below the module's low threshold. Unplug the sensor and see whether the line rises. Bank 2 is the bank without cylinder 1; the service information shows which side that is.
Quick facts
- System
- Powertrain
- Category
- Camshaft / Timing
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $200 – $400
- DIY difficulty
- Intermediate DIY
Browse every code in P0300–P0394, or start from the full code library.
What does P0347 mean?
P0347 is a voltage complaint, not a timing complaint. The engine control module (ECM) watches the signal line coming back from the 'A' camshaft position sensor on Bank 2 and expects it to swing between a high and a low level as the camshaft turns. When that line instead parks below the module's low threshold and stays there, the ECM stores P0347 and stops trusting the channel.
That distinction matters because it narrows the suspect list before you open the hood. A signal stuck at the bottom of its range is what you get when something is pulling the wire toward chassis ground: chafed insulation touching the block or a bracket, a shorted driver inside the sensor, or coolant and oil sitting in a connector body and bridging the signal pin to the ground pin. It is not what you get from a stretched timing chain or a chipped reluctor tooth — those produce a signal that is present but wrong, which is a range/performance code, not a circuit-low code.
Bank 2 is the cylinder bank that does not contain cylinder number 1, so P0347 belongs to V6, V8 and flat engines with a camshaft sensor per bank. The service information shows which physical bank that is and what has to come off. Do not copy a side from another engine family. Prove the short before the sensor is replaced, because a harness repair and a sensor replacement are different jobs and the second one is paid only if the first test failed.
Common causes
- Signal wire chafed through to the engine block, a bracket, or a heat shield
- Internally shorted Bank 2 'A' camshaft position sensor
- Oil or coolant intrusion in the sensor connector bridging the signal pin to ground
- Crushed or pinched harness section where the loom crosses the rear bank
- Corroded terminals holding the signal pin against the connector shell
- A previous repair that routed the cam sensor harness against a sharp edge
- Damaged 5-volt reference shared with the sensor, dragging the signal down with it
Symptoms
- Check engine light on with P0347 stored
- Longer cranking before the engine catches
- Rough or uneven idle shortly after a cold start
- Reduced power, as the ECM defaults to a conservative timing map
- Occasional stall at low speed on engines that need the cam signal to stay synchronized
- No obvious symptom at all on engines that fall back cleanly to the crankshaft signal
Diagnostic steps
- 1.Read freeze frame first and note engine temperature and RPM at the moment it set — a short that only appears warm behaves differently from one that is always present.
- 2.Unplug the Bank 2 'A' camshaft sensor, then key on and measure the signal pin at the harness side. If it still reads near zero volts with the sensor out of the circuit, the fault is in the wiring, not the sensor.
- 3.If that same pin rises to reference voltage with the sensor unplugged, the sensor is pulling the line down internally and should be replaced.
- 4.Check the reference and ground pins at the same connector against the published voltage for this sensor. A shared reference that has collapsed can set codes on several circuits at once, so read the full code list before condemning the cam channel.
- 5.Follow the harness from the sensor back toward the loom and look specifically where it crosses the rear bank, passes a heat shield, or is cable-tied to a metal bracket.
- 6.Inspect the connector body for oil wicking up the wires from a leaking cam seal — oil-soaked terminals are a repeat offender and cleaning alone rarely holds.
- 7.Repair or replace what you found, clear the code, and confirm the signal now toggles cleanly on a scan tool while cranking.
Repair cost
$200 – $400
Parts plus labor for the sensor when the unplug test condemns it. RepairPal's national average is about $224–$326, rounded to $200–$400. A harness short is wiring labor and can sit under that. Which bank is harder to reach is in the service information. It is not a rule that bank 2 faces the radiator.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with camshaft position sensor replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.