Damaged, chafed or corroded wiring to the knock sensor, including a short or open circuit; Poor connection or corroded terminals at the knock sensor plug or control unit connector; Faulty knock sensor, for example internal failure or cracked element; Knock sensor loose or tightened to the wrong torque, giving a weak or noisy signal; Oil, coolant or heat damage to the harness near the sensor, often under the intake manifold on some engines; Fault in the engine control unit input circuit.

P0330

Knock/Combustion Vibration Sensor B Circuit.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
3: AreaIgnition system or misfire
30: FaultThe specific fault in that area

What it means

P0330 is the generic code for a fault in the circuit of knock sensor B, which is normally the sensor on bank 2 of the engine. The engine control unit sets it when the signal from that sensor is missing, out of range or implausible, so it cannot reliably detect combustion knock on that bank.

Symptoms

Engine warning light on
Reduced power or flat feeling under load
Poorer fuel economy
Pinging or rattling under load or on poor fuel
Rough running or hesitation on acceleration
Possible limp mode on some engines

Possible causes

Damaged, chafed or corroded wiring to the knock sensor, including a short or open circuitlikely
Poor connection or corroded terminals at the knock sensor plug or control unit connectorlikely
Faulty knock sensor, for example internal failure or cracked elementlikely
Knock sensor loose or tightened to the wrong torque, giving a weak or noisy signalpossible
Oil, coolant or heat damage to the harness near the sensor, often under the intake manifold on some enginespossible
Fault in the engine control unit input circuitrare

How to diagnose

Read all stored codes and freeze frame data, noting engine load, speed and temperature when the fault set, then check for other related codes
Confirm which sensor is knock sensor B on this engine, as bank and location vary by model
Visually inspect the knock sensor wiring and connector for chafing, oil contamination, heat damage, corrosion and bent or pushed-back pins
Check the sensor is fitted correctly and tightened to the manufacturer's torque, and that its mounting surface is clean
Check the wiring for continuity, short to earth and short to voltage between the sensor and control unit, following the wiring diagram
Measure the sensor resistance or signal against the manufacturer's specification, where one is published for this model
Check the live data or a scope trace for a signal that responds when the block is tapped near the sensor
Clear the code after repair and road test under load to confirm it does not return

How to fix

Repair or replace damaged wiring and clean or renew corroded connector terminals
Replace the knock sensor if it fails electrical or signal tests, using the correct type for the engine
Refit a loose sensor with a clean mounting face and tighten to the specified torque
Replace oil-soaked or heat-damaged harness sections or the connector
Repair or replace the control unit only after all wiring and sensor faults are ruled out and the fault is confirmed

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but the engine may run with retarded timing and reduced protection against knock, so avoid heavy loads and book repair soon. Persistent knock without protection can damage the engine.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.