What Does P0333 Mean?
The knock sensor 2 on bank 2 is sending an abnormally high voltage signal to the ECM. This sensor detects engine detonation (ping/knock) and the high reading may cause the ECM to retard ignition timing excessively. The driver may notice reduced power, poor fuel economy, and sluggish acceleration as the ECM over-compensates to protect the engine from perceived knock.
Common Causes
35%
Faulty knock sensor 2 (internal short or degraded piezoelectric element producing excessive voltage)
25%
Wiring harness short to voltage or electromagnetic interference on the knock sensor 2 circuit
20%
Incorrect knock sensor torque causing resonance amplification and artificially high signal output
10%
ECM internal fault in the knock sensor signal processing circuit
10%
Engine mechanical noise (rod knock, piston slap) being detected as constant high-level knock signal
Diagnostic Steps
1
Monitor knock sensor 2 voltage with live data — normal is typically 0.5–4.5V with brief spikes during detonation events; a constant high reading (above 4.0V) points to a sensor or wiring fault.
2
Inspect the knock sensor 2 wiring harness on bank 2 for chafing, pinched wires, or contact with hot exhaust components that could cause insulation breakdown and short to voltage.
3
Disconnect the knock sensor 2 connector and measure resistance across the sensor terminals — most knock sensors read 500–600 kOhms at room temperature; readings significantly outside this range indicate a failed sensor.
4
With the sensor disconnected, check the harness for short to voltage by measuring between the signal wire and ground — there should be no voltage present with the sensor unplugged.
5
Verify the knock sensor mounting torque is within spec (typically 15–20 Nm) — over-torquing or under-torquing changes the sensor's sensitivity and can produce erratic high readings.
Estimated Repair Cost
$100 - $400
Parts + labor, varies by vehicle and location
The knock sensor 2 on bank 2 is sending an abnormally high voltage signal to the ECM. This sensor detects engine detonation (ping/knock) and the high reading may cause the ECM to retard ignition timing excessively. The driver may notice reduced power, poor fuel economy, and sluggish acceleration as ...
The most common cause of P0333 (Knock Sensor 2 Circuit High Input (Bank 2)) is: Faulty knock sensor 2 (internal short or degraded piezoelectric element producing excessive voltage)
Typical repair costs for P0333 range from $100 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Generally safe to drive short distances. The ECM will retard timing as a protective measure, which reduces power but prevents engine damage. Extended driving with excessive timing retard can increase fuel consumption and exhaust temperatures. Avoid heavy acceleration or towing until resolved.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0333 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Ignition System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
