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Fault codes › P03xx — Ignition and misfire › P0333

Fault codeP0333

SEVERE

Knock Sensor 2 Circuit High Input (Bank 2)

What this code means

Knock Sensor 2 Circuit High Input (Bank 2).

“Bank 1” is the side of the engine that holds cylinder number 1; “Bank 2” only exists on V and flat engines. An in-line engine has a single bank.

P0333 is a generic code: it means the same thing on every make. P0333 belongs to family P03xx — Ignition and misfire. Its page explains how to read a code and groups all its codes by part.

Type of fault

The control unit reads a voltage on this circuit above its expected range. Usual causes: a broken wire or a poor ground, a short to a supply voltage, or the component itself. As with a low signal, check the wiring and connector before the part.

Knock sensor

The knock sensor is a small microphone bolted to the engine block. It listens for the sharp vibration of knock, abnormal combustion that can damage pistons. When it hears it, the control unit retards the ignition timing on the cylinder concerned.

What you notice

Usually little: the control unit retards ignition as a precaution, so the engine may lack power and consume more. Audible pinging under load points to real knock.

How to check it

The sensor must be tightened to the right torque on a clean surface: too loose or too tight, it hears badly. Check its connector and wiring, often under the intake manifold. In Klaro, a timing advance that stays very low under load hints that the control unit is retarding ignition.

Watch it live in Klaro

With an OBD2 adapter plugged in, these live readings show the part at work, when your car reports them:

  • Timing advance
  • Engine RPM

What to do

Have it checked promptly. A misfire sends unburnt fuel into the exhaust and destroys the catalytic converter within a few dozen kilometres. If the light is flashing, stop driving.

Clearing a code switches the light off but repairs nothing: if the fault remains, the code comes back. Clearing a fault code yourself →

How to read this code

  • PPowertrain
  • 0standardised code
  • 3Ignition and misfire
  • 33P0333

Other codes for the same part

P0333

System
Powertrain
Fault family
Ignition and misfire
Severity
SEVERE
Origin
Standardised generic code
Read this code on your own car

Klaro shows this code and the others in plain words, alongside live engine data. An OBD2 adapter is required, sold separately.

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