Knock Sensor 1 Circuit High (Bank 1 or Single Sensor)
The knock sensor produces a small voltage from engine vibrations. The ECU uses it to tell whether there is knocking and to retard the ignition.
What the car has detected
The sensor signal is too high: it may be an electrical fault, a loose sensor or a loud mechanical engine noise the sensor mistakes for knocking.
The ECU retards the ignition and the car has less power. If the engine also makes a new metallic noise, stop and have it checked before going on.
Symptoms
- Engine warning light on
- Less power and higher fuel use
Possible causes
- Loose or faulty knock sensor
- Broken or shorted wire, or a loose or corroded connector
- Mechanical engine noise (loose or worn parts)
Checks for the garage
- Check the sensor’s tightening torque
- Check the sensor wiring and connector
- Listen to the engine for mechanical noises
Next step
Ask for the knock sensor and its wiring to be checked, and for the engine to be listened to for any mechanical noise.
Go to a garage in the next few days, sooner if the engine sounds different.