P0325 on Lexus
Knock Sensor 1 Circuit Malfunction (Bank 1)
P0325 on Lexus vehicles indicates knock sensor 1 circuit malfunction (bank 1). Au7o has documented this code across 1 Lexus model — most commonly on ES. This code indicates a fault in the knock sensor 1 circuit on Bank 1. The knock sensor listens for the vibrations of detonation (pinging/spark knock) and lets the computer retard ignition timing to protect the engine. When the sensor's signal is missing, out of range, or the circuit is open/shorted, P0325 sets. With knock detection compromised, the computer may run more conservative timing, causing reduced power and slightly lower fuel economy, and the engine is less protected against damaging knock. Typical repair costs on Lexus range from $350 to $900, depending on the specific model and root cause.
Common Causes of P0325
- •Failed knock sensor
- •Corroded or loose knock sensor connector
- •Damaged, open, or shorted sensor wiring
- •Improperly torqued or loosely mounted sensor
- •Moisture or corrosion in the connector
- •Wiring harness chafing near the engine
- •Faulty PCM/ECM (rare)
P0325 on Lexus by Model
Lexus ES(1 issue)
- XV20/XV30 ES (1MZ-FE): Knock Sensor Sub-Harness Chafes and Sets P0325 / P03301997-2003
On the 1MZ-FE V6 the two knock sensors sit in the valley between the cylinder heads, and their sub-harness bakes there under the intake manifold. The wire insulation hardens and chafes, shorting the signal wire to ground and setting P0325 (knock sensor 1 circuit) and/or P0330 (knock sensor 2 circuit). The ECU responds by pulling timing, so the car runs down on power and mileage with a permanent check engine light. The recurring forum lesson is that the harness - not the sensors - is usually the failed part: owners who replace only the sensors see the code return within days.
Looking for P0325 on a different make?
View P0325 across all makes →Frequently Asked Questions
What does P0325 mean on Lexus?▼
P0325 stands for "Knock Sensor 1 Circuit Malfunction (Bank 1)." This code indicates a fault in the knock sensor 1 circuit on Bank 1. The knock sensor listens for the vibrations of detonation (pinging/spark knock) and lets the computer retard ignition timing to protect the engine. When the sensor's signal is missing, out of range, or the circuit is open/shorted, P0325 sets. With knock detection compromised, the computer may run more conservative timing, causing reduced power and slightly lower fuel economy, and the engine is less protected against damaging knock. On Lexus specifically, this code is documented across 1 model.
What causes P0325 on Lexus vehicles?▼
Common causes on Lexus: Failed knock sensor, Corroded or loose knock sensor connector, Damaged, open, or shorted sensor wiring, Improperly torqued or loosely mounted sensor, Moisture or corrosion in the connector. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0325 on a Lexus?▼
Repair costs on Lexus range from $350 to $900, depending on the specific model and root cause.
Which Lexus models have P0325 documented?▼
Au7o has documented P0325 on 1 Lexus model: ES.