What does code P0325 mean on a Acura and is it safe to drive?
P0325: Knock Sensor 1 Circuit Malfunction (Bank 1). Here's what it means on your Acura, 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 Acura
- 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 Acura, 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 Acura
Acura P0325 on J35 V6 (MDX, TL, Pilot) mirrors Honda V6—the knock sensor connector is the most common failure point, not the sensor itself. The connector is accessible by removing the intake manifold upper plenum. On Type-S and performance variants, verify the knock sensor is fully functional before any tuning or octane testing. RDX 3.5L K24W shares Honda's connector corrosion pattern. Use OEM Denso sensors on Acura/Honda applications—aftermarket sensors with incorrect resonant frequencies can cause constant timing retard without setting any codes.
Most commonly affected models