What are the symptoms of P0340?

Common symptoms include: Hard start / long crank; Stalling; Rough running.

What causes a P0340 code?

The most common causes are: Failed cam position sensor; Wiring/connector fault; Damaged sensor tone ring.

How do you fix P0340?

Check the cam signal on a scan tool; Inspect wiring and the connector; Replace the sensor if no signal. Worth diagnosing soon — left alone, the underlying issue can grow into a bigger, costlier problem.

OBD-II Code Lookup

P0340Watch

Camshaft Position Sensor Circuit

Electrical system

The camshaft position signal is missing or faulty. The computer uses it (with the crank signal) for timing; a fault can cause hard starts or stalling.

Worth diagnosing soon — left alone, the underlying issue can grow into a bigger, costlier problem.

Common symptoms

Hard start / long crank
Stalling
Rough running

Common causes

Failed cam position sensor
Wiring/connector fault
Damaged sensor tone ring

How it's diagnosed & fixed

Check the cam signal on a scan tool
Inspect wiring and the connector
Replace the sensor if no signal

Got P0340? Get it diagnosed.

A real technician can interpret P0340 in the context of your truck and symptoms — and tell you what's actually wrong before you buy parts.

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Related Electrical codes

P0335Crankshaft Position Sensor Circuit P0606ECM/PCM Processor Fault P0521Engine Oil Pressure Sensor/Switch Range/Performance P0562System Voltage Low

Reference only. A trouble code names a symptom, not the failed part — always confirm with a live diagnosis before repairs. See our Knowledge Base for deeper guides.