2021 Hyundai P0325: What It Means & Is It Safe to Drive?
P0325 on the 2021 Hyundai: Knock Sensor 1 Circuit Malfunction (Bank 1). Here's what it means, what usually causes it, what repairs typically cost, and whether it's safe 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 on the 2021 Hyundai
- 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 2021 Hyundai, repairs for P0325 typically fall between $150 and $500, depending on the root cause and labor rates in your area.
Known issues on Hyundai
Hyundai P0325 on Theta II engines should be taken seriously—given the known rod bearing failure issue on these engines, the knock sensor circuit should be fully functional. A failing knock sensor on a Theta II engine means the PCM cannot detect actual engine knock, which accelerates bearing damage. Verify the Theta II recall is complete on your VIN before assuming P0325 is just a sensor failure. On Genesis Coupe 2.0T, the knock sensor is accessible without major disassembly; check the sensor mounting torque first.
Most commonly affected models