The code appeared right after I had work done. Is that a coincidence?

Very likely not. An unplugged or partially latched sensor connector reads exactly the same as a failed sensor to the module, and Bank 2 is often the bank that gets disturbed to reach something else. Check that the connector is fully seated before spending money.

Why should I test the ground instead of the signal wire?

Because the sensor works by pulling the signal line toward ground. If the ground path is open or corroded, the sensor cannot pull the line down and the module sees it stuck high, even though the signal wire itself is fine. A voltage drop test across the ground finds this; a continuity check often misses it.

What is the difference between P0348 and P0347?

They are opposite ends of the same measurement. P0347 means the signal is stuck low, which points at a short to ground. P0348 means it is stuck high, which points at an open circuit, a missing ground, or a sensor that has stopped switching.

Could a bad reluctor ring set P0348?

Yes, though it is less common than wiring faults. If the toothed ring on the camshaft has spun, sheared, or lost its teeth, the sensor has nothing to react to and its output never toggles. Pull the sensor and look at the ring before assuming the sensor is dead.

OBD-II trouble code

P0348: Camshaft Position Sensor 'A' Circuit High (Bank 2)

The Bank 2 'A' camshaft sensor signal is stuck at the top of its range. An unplugged connector produces exactly this reading, which makes P0348 the classic code to appear right after other work was done in the area.

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: $0 – $400
DIY difficulty: Intermediate DIY

What does P0348 mean?

Most camshaft position sensors are wired so the engine control module (ECM) supplies a reference voltage and the sensor pulls that line down toward ground each time a reluctor tooth passes. Read that arrangement backwards and it tells you what P0348 means: the line is sitting high because nothing is pulling it down. Either the sensor is not switching, or the circuit that lets it switch — most often the ground side — is open.

That is why P0348 is more frequently a ground or open-circuit fault than a signal-wire fault, which is the opposite of the intuition most people bring to it. A broken ground leaves the sensor electrically stranded even though its signal wire is perfectly intact, and a multimeter on the signal wire alone will happily show a healthy reference voltage while telling you nothing useful. Voltage drop measured across the ground side is the test that actually separates these.

There is a second consequence worth knowing. Because a disconnected sensor reads high, P0348 is the code that shows up after somebody has been working nearby — an intake manifold gasket, a valve cover, a rear-bank spark plug job, an alternator on some layouts. If this code appeared within a few days of service on the Bank 2 side of the engine, check for a connector that was never fully latched before you buy anything. On V6 and V8 engines Bank 2 is the bank without cylinder number 1, and it is routinely the bank that has to be disturbed to reach something else.

Common causes

Connector left unlatched or partially seated after nearby service work
Open or high-resistance ground circuit for the Bank 2 'A' camshaft sensor
Broken signal wire, or a terminal backed out of the connector body
Failed sensor that no longer switches its output
Corroded terminals adding resistance until the ECM reads the line as high
Rodent damage to the harness section crossing the rear of the engine
Reluctor ring that has slipped or lost its teeth entirely, so nothing triggers the sensor

Symptoms

Check engine light on with P0348 stored
Extended cranking, and on some engines a no-start until sync is regained
Stumble or hesitation shortly after starting
Reduced power with the engine running in a limp or default timing strategy
Symptoms that began immediately after unrelated engine work was performed
No driveability complaint at all on engines that infer position from the crank signal

Diagnostic steps

1.Before testing anything, ask what was done to the engine recently. A P0348 that appeared right after service on the Bank 2 side is an unlatched connector until proven otherwise.
2.Pull the connector, look at the terminals for spread, corrosion, or one pushed back out of its cavity, then reseat it firmly and see whether the code returns.
3.Measure voltage drop across the sensor ground circuit with the key on rather than just checking for continuity — a corroded ground can pass a continuity test and still fail under load.
4.Confirm reference voltage is present at the connector. If reference is good and ground is good, the sensor is not switching and is the likely fault.
5.Back-probe the signal wire while cranking and watch for any toggle. A flat line at reference voltage with a known-good sensor installed points at an open between the sensor and the module.
6.If the circuit checks out end to end, remove the sensor and inspect the reluctor ring it reads — a ring that has spun on the camshaft gives the sensor nothing to trigger on.
7.After the repair, verify the signal switches on a scan tool and confirm no crank-to-cam correlation codes remain.

Repair cost

$0 – $400

A connector that was simply not latched costs nothing to fix. A failed sensor is generally $40 to $200 in parts with half an hour to two hours of labor depending on Bank 2 access. Open-circuit repairs — repinning a terminal or splicing a broken wire — usually land between $80 and $220 once diagnostic time is included.

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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.