What causes P0325 on a Hyundai Elantra?

Common causes of P0325 on Hyundai Elantra: Failed knock sensor (very common on Theta II engines); Knock sensor wiring harness damage from engine heat; Engine knock from low-octane fuel or carbon buildup; Theta II engine rod bearing wear causing real knock detected by sensor; Corroded knock sensor connector.

P0325

P0325 Hyundai Elantra

Q: How much does it cost to fix P0325 on a Hyundai Elantra?

Fixes for P0325 on Hyundai Elantra include: Replace knock sensor (Hyundai Genuine; located under intake manifold), Inspect knock sensor wiring for damage from heat or chafing, Perform engine oil analysis to check for bearing material, Use recommended octane fuel and check for carbon buildup, Listen for rod knock at idle; if present, inspect bearings (Theta II recall).

Knock Sensor 1 Circuit Malfunction (Bank 1) · Powertrain Code · Medium

What is P0325?

The knock sensor 1 on bank 1 is not functioning properly. The ECM cannot detect engine knock/detonation.

When the Hyundai Elantra triggers code P0325 (knock sensor 1 circuit malfunction (bank 1)), it typically points to an issue in the powertrain system. Below you'll find the most common causes, symptoms, and repair options specific to the Hyundai Elantra.

Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Hyundai Elantra.

Common Causes on Hyundai Elantra

Failed knock sensor (very common on Theta II engines)
Knock sensor wiring harness damage from engine heat
Engine knock from low-octane fuel or carbon buildup
Theta II engine rod bearing wear causing real knock detected by sensor
Corroded knock sensor connector

Symptoms

Check Engine Light on
Reduced engine power (ECM retards timing)
Slightly worse fuel economy
Engine may feel sluggish on acceleration

Recommended Fixes

Replace knock sensor (Hyundai Genuine; located under intake manifold)

Inspect knock sensor wiring for damage from heat or chafing

Perform engine oil analysis to check for bearing material

Use recommended octane fuel and check for carbon buildup

Listen for rod knock at idle; if present, inspect bearings (Theta II recall)

Notes for Hyundai Elantra

On Theta II engines, a knock sensor code can indicate the beginning of rod bearing failure; always investigate further.

P0325 Hyundai Elantra

What is P0325?

Common Causes on Hyundai Elantra

Symptoms

Notes for Hyundai Elantra

Check Hyundai Elantra Specs