A short to voltage on the sensor signal wire, often where the harness rubs against a bracket or heat source; A damaged, corroded, or water-intruded camshaft sensor connector causing the signal line to read high; A failed camshaft position sensor that internally pulls the signal circuit toward supply voltage; A poor ground or reference voltage fault at the sensor, skewing the signal the computer reads; A wiring harness fault such as a pinched wire behind the engine or near the timing cover; A faulty engine computer driver on the sensor input circuit, which is rare but possible

DTC codes / P03xx · Ignition system and misfire / P0348

P0348Camshaft Position Sensor 'A' Circuit High

Q: What does code P0348 mean?

Camshaft Position Sensor 'A' Circuit High. P0348 means the engine computer detected a voltage on the camshaft position sensor 'A' circuit that stayed above its expected maximum for the conditions, so it cannot trust the camshaft timing signal. The sensor reports the camshaft's position and speed to the computer, which uses it to sequence fuel injection and spark; a high circuit usually points to a wiring or connector problem rather than a failed sensor.

P0348 means the engine computer detected a voltage on the camshaft position sensor 'A' circuit that stayed above its expected maximum for the conditions, so it cannot trust the camshaft timing signal. The sensor reports the camshaft's position and speed to the computer, which uses it to sequence fuel injection and spark; a high circuit usually points to a wiring or connector problem rather than a failed sensor.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Illumination of the check engine light, often with no other symptoms besides the warning light
Intermittent or complete engine stall, especially at idle or when coming to a stop
Rough running, misfiring, or a noticeable loss of power under acceleration
Hard starting or a crank-but-no-start condition when the signal is lost entirely
Poor fuel economy or increased emissions as the computer defaults to a guessed timing strategy

Common causes, most likely first

A short to voltage on the sensor signal wire, often where the harness rubs against a bracket or heat source
A damaged, corroded, or water-intruded camshaft sensor connector causing the signal line to read high
A failed camshaft position sensor that internally pulls the signal circuit toward supply voltage
A poor ground or reference voltage fault at the sensor, skewing the signal the computer reads
A wiring harness fault such as a pinched wire behind the engine or near the timing cover
A faulty engine computer driver on the sensor input circuit, which is rare but possible

How to diagnose and fix it

Scan all stored and pending codes and record freeze-frame data to confirm P0348 is the primary fault rather than a side effect
Inspect the camshaft sensor connector and the full harness run for chafing, corrosion, or pushed-out pins
Measure reference voltage, ground continuity, and signal voltage at the sensor connector with the key on and during cranking
Back-probe the signal wire at the computer to compare it with the sensor-end reading and isolate a wiring fault
Check the sensor's resistance or waveform against the manufacturer's specification, replacing it only if it fails
Repair or replace the damaged section of harness and clear the code, then verify the signal with a scan tool or oscilloscope
If the circuit tests good at the computer but the code returns, test the computer input circuit before condemning the module

Why this code is rarely the sensor itself

A high circuit code most often means the signal wire is shorted to voltage or the connector has lost its ground, so replacing the sensor first usually wastes money.
A loose or contaminated camshaft sensor connector can read high intermittently, and the code may only set on bumpy roads or after the engine bay gets wet.
Some vehicles set P0348 when the timing belt or chain has jumped, because the camshaft signal arrives outside the window the computer expects even though the circuit is intact.
A failing crankshaft position sensor or a shared reference voltage fault can drag the camshaft signal high, so check related sensor circuits before condemning the cam sensor.
Clearing the code without repairing the circuit often brings it back within a few drive cycles, and the engine may run poorly in the meantime because the computer is guessing cam timing.

Can I keep driving with P0348?

You can usually drive a short distance to a repair shop if the engine runs normally, but avoid long trips, heavy loads, and sustained high speeds because a lost camshaft signal can cause stalling or a no-start. If the engine is misfiring, stalling, or hard to start, stop driving and have the circuit diagnosed before further use.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.