Knock sensor
P2347 Knock sensor: knock above threshold (cylinder 12)
P2347 means: Knock sensor: knock above threshold (cylinder 12). The knock sensor listens for engine knock. Drive gently and have the car checked soon. The most common repair costs about €80–160 in Estonia, depending on make and model. The most common cause: faulty or loose sensor.
Is it safe to drive?Get it checked soonDrive gently and have the car checked soon.
Sensor replacement€80–160parts and labour in Estonia, depending on make and model
What it means
The knock sensor listens for engine knock. If its signal is wrong, the computer retards the ignition to be safe and the engine loses power.
What you may notice
- Engine light on
- Less power
- Slightly higher fuel consumption
What could be wrong
- 1Faulty or loose sensor · Sensor replacement €80–160
- 2Sensor wire or connector · Sensor replacement €80–160
- 3Fuel octane too low · Fuel system check €45–90
- 4Real knock (carbon build-up, overheating) · Diagnosis and checks €45–90
Repair difficulty: Moderate
What you can check yourself
Fill up with the right octane fuel. The sensor is often on the block under the intake, so it may be hard to reach. You can check the simple things yourself, but the repair is best done in a workshop.
How we fix it
- We read the sensor on the diagnostic tool and compare it with other sensors
- We check the connector, supply and ground
- We repair the wiring or replace the sensor
Standard SAE description: Cylinder 12 Above Knock Threshold