How do I tell whether it's the sensor or the wiring?

Unplug the sensor and measure the signal pin on the harness side with the key on. If the voltage climbs back up to reference, the sensor was dragging it down and the sensor is at fault. If it stays low with nothing plugged in, the wire is shorted to ground somewhere and a new sensor will not fix it.

Why does P0347 usually mean a short rather than a timing problem?

Because it is a voltage-range fault. A timing problem produces a signal that is present but arrives at the wrong crank angle, which sets a correlation or range/performance code instead. A signal pinned at the bottom of its range means something is holding the wire near ground.

Which side of the engine is Bank 2?

It is the bank that does not contain cylinder number 1. On many transverse V6 engines that is the rear bank against the firewall, which is why this repair often costs more in labor than its Bank 1 twin even though the part is identical.

Can I keep driving with P0347?

Short trips are usually possible because most engines keep running on the crankshaft signal, but a shorted signal wire can worsen and take the circuit down completely. If the car is cranking longer than normal or stumbling, get it looked at before it leaves you somewhere inconvenient.

OBD-II trouble code

P0347: Camshaft Position Sensor 'A' Circuit Low (Bank 2)

Voltage on the Bank 2 'A' camshaft sensor signal wire is sitting below the range the engine computer accepts. Usually a short to ground in the harness or a shorted sensor, and it is separable from a bad sensor with one unplug test.

Medium severityPowertrainCamshaft / TimingDrivable short-term

Quick facts

System: Powertrain
Category: Camshaft / Timing
Severity: Medium severity
Drivable: Usually safe to drive short-term
Repair cost range: $60 – $450
DIY difficulty: Intermediate DIY

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. On transverse V6 installations, Bank 2 is very often the rear bank tucked against the firewall, and that single geographic fact drives most of the cost of this repair — the part is inexpensive, the reach is not. Get the diagnosis right before you commit to the labor, because replacing a rear-bank sensor to fix a harness short means paying that reach twice.

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 5-volt reference and ground pins at the same connector. A collapsed reference shared with other sensors usually sets codes on several circuits at once, so scan 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

$60 – $450

The sensor itself is usually $40 to $200. Labor is the variable: an accessible Bank 2 sensor is well under an hour, while a firewall-side sensor on a transverse V6 can take two or more once the intake or cowl trim comes off. Harness repairs typically run $80 to $250 depending on how much loom has to come apart to reach the damaged section.

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Open the Repair Cost Estimator with camshaft position sensor replacement preselected. Adjust labor rate and vehicle category to fit your situation.

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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.