What does code P0325 mean on a Mazda and is it safe to drive?
P0325: Knock Sensor 1 Circuit Malfunction (Bank 1). Here's what it means on your Mazda, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
What this code means
The PCM isn't receiving a valid signal from knock sensor 1. Without knock feedback, the PCM retards ignition timing as a safety measure, reducing power and economy.
Common causes for your Mazda
- Failed knock sensor
- Corroded or broken wiring/connector at the sensor
- Actual engine knock from carbon buildup or low-octane fuel
Symptoms
- Check Engine Light
- Reduced power and fuel economy (PCM retards timing)
- Possible audible knock or ping under load
Typical fixes
- Replace knock sensor
- Repair wiring and connector
- Use correct octane fuel and address carbon buildup
Repair cost range
For a Mazda, repairs for P0325 often fall between $150 and $500, depending on the cause and whether you use OEM or aftermarket parts. Labor rates vary by location.
Known issues on Mazda
Mazda P0325 on SkyActiv-G engines is uncommon—these engines have robust knock sensor systems. When P0325 appears, check the sensor mounting torque first (SkyActiv knock sensors require 17–20 Nm torque to read correctly; under- or over-torqued sensors give incorrect signals or set P0325). On older Mazda3 2.3L (L3-VE) and Mazda6 2.3L, P0325 is more common due to heat-related harness degradation near the exhaust. On Mazdaspeed3 2.3T, a functional knock sensor is critical—do not drive with P0325 on a turbocharged Mazda.
Most commonly affected models