P0333 — Knock Sensor 2 Circuit Low Input (Bank 2)
Drive with caution — fix soon.
What P0333 means
This code means the voltage from the bank 2 knock sensor circuit is lower than expected, often pointing to an open or shorted wire, a bad connection, or a failed sensor. Because the computer can't trust the sensor, it usually defaults to a safer, more conservative ignition timing. The typical fix is repairing the wiring or connector and replacing the knock sensor if needed.
Common symptoms
- Check engine light is on
- Reduced engine power or sluggish response
- Lower than usual fuel economy
- Possible knocking or pinging under load
- Engine may feel slightly rough during acceleration
Common causes
- Open or short to ground in the sensor wiring
- Failed knock sensor on bank 2
- Corroded or disconnected electrical connector
- Damaged wiring harness near the sensor
- Faulty engine control module (rare)
Typical repair cost
$150 – $400
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0333 code?
Usually yes for the short term. The car remains drivable, though it may feel a touch less powerful. Get it diagnosed soon and avoid aggressive acceleration in the meantime.
How much does it cost to fix a P0333 code?
Most repairs land between $150 and $400. If it's just a wiring or connector fix, it can be on the lower end; replacing a sensor buried under the intake manifold pushes it higher.
Is a P0333 code serious?
It's moderate. There's no immediate danger of breakdown, but without a working knock sensor the engine runs more conservatively and isn't fully protected against detonation, so it's worth addressing.
What causes a low input reading on a knock sensor?
A low input usually means the signal voltage has dropped too far, often from a broken or shorted wire, a corroded connector, or a sensor that has failed. A technician will test the circuit to pinpoint which it is.