How much does it cost to fix P0340 on a Ford?

Repair costs for P0340 on Ford vehicles typically range from $120 to $350 depending on the underlying cause. The most common fix is: Camshaft position sensor failure or oil-fouled connector.

Ford Check Engine Code

P0340 on Ford

Camshaft Position Sensor A Circuit Malfunction (Bank 1 or Single Sensor)

Severity: high DIY difficulty: 2/5 Ford cost: $120–$350

Last updated April 30, 2026 Also covers: Lincoln, Mercury

P0340 on Ford: what makes it different

P0340 (camshaft position sensor circuit malfunction) shows up often on Ford's Duratec and early EcoBoost engines, where the CMP sensor sits in a tight spot near the valve cover and is prone to oil contamination or connector wear over time.

Most-affected engines

Duratec 2.0L/2.5L (Fusion, Escape, Focus)
EcoBoost 1.6L/2.0L (Escape, Fusion, Explorer)
Modular V8 (F-150, Mustang) on older model years

Common model years: 2008–2017

Most likely cause on Ford

Camshaft position sensor failure or oil-fouled connector

Known Ford engine-family issues

On several Ford four-cylinder engines, a slow valve cover gasket seep is a known contributor to CMP sensor failure since oil migrates into the connector over years of service, so it's worth inspecting the valve cover gasket whenever this code appears.

Ford-specific causes (most common first)

Camshaft position sensor itself failing internally with age/heat cycling
Oil leaking onto the sensor connector from a valve cover gasket seep
Wiring harness chafing near the sensor due to tight routing in the engine bay
Timing chain stretch on higher-mileage EcoBoost engines affecting signal timing
Corroded connector pins from engine bay moisture intrusion
Loose sensor mounting bolt causing intermittent signal dropout

Ford-specific diagnostic tip

Before replacing the sensor, unplug the connector and check for oil residue or corrosion on the pins — on Ford four-cylinders this is a very common root cause, and cleaning/sealing the connector area can sometimes resolve the code without a new sensor.

Symptoms drivers report

Check engine light
Hard starting or no start
Stalling
Loss of power
Erratic idle

Typical repair cost on Ford

Most Ford owners fix P0340 for between $120 and $350, depending on which underlying cause turns out to be at fault. Start with the most-likely cause for your vehicle — Camshaft position sensor failure or oil-fouled connector — before throwing parts at it.

Ford P0340 FAQ

Can P0340 cause my Ford to stall or not start?

Yes, in some cases, since the PCM relies on camshaft position data for fuel injection timing — a fully failed sensor can cause hard starting or stalling, especially on EcoBoost engines.

Is this related to the timing chain on EcoBoost engines?

It can be indirectly — chain stretch changes the cam-to-crank relationship enough to throw correlation or CMP codes, which is more common on higher-mileage EcoBoost engines than on the Duratec.

Do I need a dealer scan tool to diagnose this on a Ford?

No, a basic OBD2 scanner can read the code, but confirming whether it's sensor wiring versus timing-related often benefits from checking live cam/crank signal waveforms.