Knock Sensor 1 Circuit Malfunction (Bank 1 or Single Sensor)
What it means
The knock sensor picks up vibrations caused by premature ignition so the computer can retard spark timing to protect the engine. When its signal is lost, the computer retards timing as a precaution, reducing performance and raising fuel use.
Symptoms4
- Weaker pulling and acceleration.
- Higher fuel consumption.
- Pinging under load in some cases.
- Check engine light on.
Possible causes4
- Failed knock sensor.
- Broken or corroded sensor wiring, often under the intake manifold.
- Corroded connector or water or oil ingress.
- Incorrect sensor mounting torque.
How to diagnose and fix5
- Inspect the sensor connector and wiring.
- Measure sensor resistance or signal according to its type.
- Make sure the sensor is tightened to the specified torque, as over- or under-tightening changes its sensitivity.
- Replace the sensor and any damaged wiring.
- Clear the code and test drive to confirm it does not return.
Repair cost
In Saudi riyals; the highlighted part is the expected range for this fault.
The sensor is fairly cheap, but on some engines it sits under the intake manifold, pushing labor into the second 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
Can this code damage the engine?
The computer protects the engine by retarding timing, so direct damage is unlikely. If you hear clear knocking, reduce load and use the recommended fuel grade.
Why is the repair expensive on my car?
On some engines the sensor sits in the valley under the intake manifold, requiring lengthy disassembly to reach it.
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.
Report a mistake
Spotted something inaccurate? Tell us and we will review and correct it.
Report received — thank you
This is your private tracking link. It shows the status and our reply as soon as it is posted.
The link is saved in this browser only.