Crankshaft Position Sensor A Circuit Malfunction

What it means

The crankshaft sensor tells the computer engine speed and piston position; without it the computer does not know when to fire the spark and injectors. This code means its signal is missing or erratic, which can make the engine stall or refuse to start.

Symptoms5

• Engine cranks but will not start.
• Sudden stalling while driving, often once the engine is warm.
• Intermittent stumbling and shaking.
• Tachometer does not move while cranking.
• Check engine light on.

Possible causes5

• Failed crankshaft sensor, often heat-sensitive.
• Corroded or oil-soaked sensor connector.
• Broken or chafed wiring.
• Damaged reluctor ring teeth on the crankshaft (rare).
• Incorrect sensor gap after a previous repair.

How to diagnose and fix5

1. Inspect the sensor connector and wiring, checking for oil inside the plug.
2. Watch the engine speed signal on a scan tool while cranking.
3. Test the sensor with a meter or oscilloscope depending on its type.
4. Replace the sensor with a good-quality part, since cheap sensors fail often.
5. If the code persists, check the reluctor ring and the wiring back to the computer.

Repair cost

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

The sensor is usually inexpensive, but labor rises on engines where it is hard to reach.

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

Frequently asked questions