P0326

Knock Sensor 1 Circuit Range/Performance (Bank 1 or Single Sensor)

Car Fault Codes Ignition & misfire

Can you still drive? With care, short trips only

Who can fix it? Needs a workshop

Typical repair time 30 minutes – 4 hours

Typical cost SAR 100 to 900

What it means

The knock sensor 1 circuit is electrically intact, but the engine computer finds that its signal does not match what it expects from the engine under current conditions. The cause may be a weak or badly mounted sensor, or real mechanical noise in the engine that confuses the reading.

Symptoms4

Check engine light on.
Reduced performance from retarded ignition timing.
Pinging sound from the engine when accelerating or climbing in some cases.
Higher fuel consumption.

Possible causes6

Weak or internally damaged sensor.
Sensor tightened to the wrong torque, or rust or dirt between it and the mounting surface.
Mechanical engine noise, such as a loose nearby part, valve noise or timing chain noise.
Real detonation from low-octane fuel, carbon deposits or engine overheating.
Electrical interference on the sensor wiring from nearby ignition wires.
Corroded connector weakening the signal.

How to diagnose5

Listen for abnormal mechanical noises or pinging under load.
Confirm the fuel grade used and that engine temperature is normal.
Check the sensor mounting, surface condition and torque against the manufacturer specification.
Inspect the connector and wire routing, making sure it is away from ignition wires.
Compare the sensor signal on an oscilloscope with the other bank's sensor, if fitted.

How to fix6

Use the recommended octane fuel and fix any overheating.
Clean the mounting surface and retighten the sensor to the correct torque.
Repair any source of mechanical engine noise.
Repair the connector or reroute the wiring away from interference.
Replace the knock sensor if it is proven weak.
Clear the codes, drive under moderate load and confirm the code does not return.

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.

The fix may be a change of fuel or retightening the sensor at little cost; it rises if a new sensor in a hard-to-reach location is needed.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions

Does this code mean the engine is really knocking?

Not necessarily. The sensor itself may be weak, but if you hear pinging under load, fix the knock first because it can damage the pistons.

Does fuel grade affect this code?

Yes. Fuel with lower octane than recommended causes early combustion that the sensor picks up, so use the grade stated in the owner's manual.

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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