P0340

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

Car Fault Codes Powertrain

Can you still drive? With care, short trips only

Typical cost Under SAR 5,000

What it means

The camshaft sensor reports camshaft position so the computer knows which cylinder is on its power stroke and can time the injectors and spark. When its signal is lost, the engine may start with difficulty or run in a backup mode with reduced performance.

Symptoms5

Long cranking or hard starting.
General loss of performance.
Intermittent stalling.
Higher fuel consumption.
Check engine light on.

Possible causes5

Failed camshaft sensor.
Damaged sensor connector or wiring.
Oil leaking into the sensor connector.
Stretched or jumped timing chain or belt.
Weak battery causing low voltage during cranking.

How to diagnose and fix5

Check battery condition and voltage during cranking.
Inspect the sensor connector and wiring and make sure they are free of oil.
Watch the sensor signal with a scan tool or oscilloscope.
Replace the sensor if it is proven faulty.
If crank and cam correlation codes also appear, have the engine timing checked.

Repair cost

0–500

500–2,000

2,000–5,000

5,000+

In Saudi riyals; the highlighted part is the expected range for this fault.

A sensor replacement is usually in the lowest tier, but a timing chain or belt fault can push the cost into the third tier.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.

Frequently asked questions

Is the camshaft sensor the same as the crankshaft sensor?

They work together, but the crank sensor measures engine rotation while the cam sensor identifies cylinder phase. Many engines can run without the cam signal in a backup mode, but not without the crank signal.

I replaced the sensor and the code remains. Why?

Usually a wiring problem or incorrect engine timing. Have the timing checked before driving further, because a jumped chain can cause major damage.

This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

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