Is it safe to drive with this code?

Short journeys may be manageable, but the knock sensor plays a vital role in protecting your engine from detonation damage. Continued driving with a faulty sensor can lead to reduced power, poor fuel economy, and potential engine harm—refer to our disclaimer and seek prompt diagnosis.

It may do. If your engine management light (MIL) is illuminated at the time of the MOT test, this is now classed as a major fault under current MOT rules. The code itself does not automatically fail the test, but the warning light does—see our disclaimer for more detail.

Roughly how much does it cost to fix?

Costs typically fall in the low‑to‑mid three‑figure range. Sensor parts may be in the low two‑figure band, but labour can vary widely depending on accessibility—sensors buried deep in a V‑engine often require removal of intake components or manifolds, pushing the total toward mid or even high three‑figure territory at main dealers. Independent garages usually quote 30% less.

Can I ignore it if the light goes off on its own?

An intermittent fault suggests the problem is still present but not constant. Ignoring it may allow the underlying issue—be it corroded wiring or a failing sensor—to worsen, potentially leading to more expensive engine repairs or reduced performance over time.

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← All fault codes | Electrical & Sensors

P0329

Powertrain

Knock Sensor Circuit Intermittent (Bank 1)

The engine control module has detected an intermittent or unreliable signal from the knock sensor on Bank 1, which typically monitors engine vibrations to protect against damaging detonation.

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ⓘ Information only. This page provides general educational information about fault code P0329. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.

Recommended next steps

Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.

What does P0329 mean?

P0329 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Knock Sensor Circuit Intermittent (Bank 1).

This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.

About Electrical & Sensors codes

Codes in the Electrical & Sensors category.

P0329 is one of 4,010 codes in this category. Browse all Electrical & Sensors codes →

What we know about P0329 specifically

We record the SAE J2012 standardised definition and the system this code belongs to, but we have not yet published detailed driver-reported symptoms, common causes, or step-by-step diagnostic guidance for P0329.

Rather than invent that information by generating generic content from a template, we leave it out. For specific guidance, the most reliable sources are:

•your vehicle's own service manual or manufacturer-specific technical bulletins
•a qualified mechanic with a manufacturer-level diagnostic tool
•a marque specialist familiar with your make and model

Codes nearby

Codes adjacent to P0329 in the P-code series. Many fault codes appear together with their neighbours because they relate to the same circuit or component.

P0326 Knock Sensor 1 Circuit Range/Performance (Bank 1)

P0327 Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor)

P0328 Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor)

P032A Knock Sensor 3 Circuit Malfunction (Bank 1)

P032B Knock Sensor 3 Circuit Range/Performance (Bank 1)

P032C Knock Sensor 3 Circuit Low (Bank 1)

Other Electrical & Sensors codes

Other fault codes in the same system as P0329. The ones with detailed guides have plain-English explanations, symptoms, causes, and diagnostic steps.

B1257

Air Temperature External Sensor Circuit Short To Ground Detailed guide

B1363

DBPT Circuit Short To Ground Detailed guide

B2100

Ignition Run/Start Input Circuit Performance Detailed guide

C2000

Steering Angle Sensor Not Calibrated Detailed guide

P0030

HO2S Heater Control Circuit (Bank 1 Sensor 1) Detailed guide

P0031

Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1) Detailed guide

Spotted an issue or have something to add? Mechanics, technicians, and drivers who have first-hand experience with P0329 can submit a correction or expansion. We review every submission before publishing, mechanic submissions are prioritised.

Information only, not professional advice

The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →

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