What does code P0340 mean?

P0340 — Camshaft Position Sensor (CMP) circuit fault. Engine doesn't know when to inject fuel to specific cylinders — falls back to synchronous injection, fuel economy worsens. Belongs to the powertrain.ignition system. Severity: warning.

What are the common causes of P0340?

Break in CMP wiring; Signal wire shorted to ground; Failed CMP sensor — typical replacement; Damaged reluctor on the camshaft; Corroded CMP connector

Can I drive with code P0340?

Limited: reaching the nearest workshop is fine, but avoid long trips. May progress into a more serious fault.

How do I diagnose P0340?

Read the code and freeze-frame with a scanner, check related-system errors, inspect the components listed (wiring, connectors, sensors). See the "How to diagnose" section above for the full step-by-step.

How do I clear code P0340?

The code can be cleared via an OBD-II scanner (e.g. ELM327 + the Car Diagnostics app): plug the adapter into the OBD port, go to Errors → Clear. If the underlying cause isn't fixed, the code will return within a few drive cycles.

OBD-II Code P0340 — Car Diagnostics Platform

What it means

Common causes

Break in CMP wiring
Signal wire shorted to ground
Failed CMP sensor — typical replacement
Damaged reluctor on the camshaft
Corroded CMP connector
Miswired after head service

How to diagnose

01
Read all stored and pending codes with an OBD-II adapter — get the full picture, not just the one code.
02
Capture freeze-frame data (RPM, coolant temperature, engine load) at the exact moment the code triggered.
03
Inspect the named subsystem with our app's AI explanation — get vehicle-specific causes for your make, model and year.

Decode P0340 on your actual car

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