P0325: Knock sensor 1 circuit malfunction (bank 1)
A knock sensor’s signal is missing or out of range. The engine computer uses it to hear knocking (pinking) and retard the ignition before it does damage; without it, the engine computer usually retards the ignition as a precaution.
Updated
What P0325 means
Knocking, or pinking, is part of the fuel and air in a cylinder igniting on its own, instead of burning smoothly from the spark. It sounds like a metallic rattle under load, and heavy knocking can damage the engine. A knock sensor on the engine block hears it, and the engine computer then retards the ignition until it stops.
P0325 means the signal from knock sensor “A” is missing or out of range. The code means the sensor can’t report knocking, not that the engine is knocking. Without it, the computer usually retards the ignition as a precaution, which costs some power and fuel.
P0326 to P0334, and sensors C and D
The codes come in fives per sensor: circuit, range/performance, low, high and intermittent. P0325 to P0329 are sensor A, P0330 to P0334 sensor B (on V engines often the sensor for bank 2), P032A to P032E sensor C and P033A to P033E sensor D, on engines that have that many. The meaning, causes and advice are the same for each. A range/performance code can also come from a loose sensor or unusual mechanical noise in the engine.
P0326: Knock/Combustion Vibration Sensor A Circuit Range/Performance
P0327: Knock sensor 1 circuit low input (bank 1)
P0328: Knock/Combustion Vibration Sensor A Circuit High
P0329: Knock/Combustion Vibration Sensor A Circuit Intermittent
P0330: Knock/Combustion Vibration Sensor B Circuit
P0331: Knock/Combustion Vibration Sensor B Circuit Range/Performance
P0332: Knock/Combustion Vibration Sensor B Circuit Low
P0333: Knock/Combustion Vibration Sensor B Circuit High
P0334: Knock/Combustion Vibration Sensor B Circuit Intermittent
P032A: Knock/Combustion Vibration Sensor C Circuit
P032B: Knock/Combustion Vibration Sensor C Circuit Range/Performance
P032C: Knock/Combustion Vibration Sensor C Circuit Low
P032D: Knock/Combustion Vibration Sensor C Circuit High
P032E: Knock/Combustion Vibration Sensor C Circuit Intermittent
P033A: Knock/Combustion Vibration Sensor D Circuit
P033B: Knock/Combustion Vibration Sensor D Circuit Range/Performance
P033C: Knock/Combustion Vibration Sensor D Circuit Low
P033D: Knock/Combustion Vibration Sensor D Circuit High
P033E: Knock/Combustion Vibration Sensor D Circuit Intermittent
Can I keep driving?
Drive gently
Drive gently and have it checked soon. The engine computer can’t hear knocking (pinking) now, and knocking under heavy load can damage the engine. Avoid hard acceleration, towing and heavy loads, and use the fuel grade your handbook asks for. If you hear the engine knocking or pinging, ease off and stop when it’s safe to do so.
General guidance based on the code alone, not on the car’s actual condition. If in doubt, stop and ask a mechanic.
The car usually drives normally, with a little less power. The risk is knocking the engine computer can no longer hear, for example under heavy load, when towing, or with fuel of a lower grade than the handbook asks for, and heavy knocking can damage the engine. Avoid heavy loads until it’s fixed, and if you hear knocking or pinging, ease off and stop when it’s safe to do so.
Symptoms
- Often just the check engine light.
- Slightly less power, slower acceleration and higher fuel use.
- Pinging or knocking when accelerating, on some cars.
Common causes
- Faulty knock sensor. A sensor that has failed gives no usable signal, even on an engine that runs fine.
- Wiring or connector fault. On some engines the sensor sits under the intake manifold, where its wiring is hard to reach and can corrode.
- Fault in the engine computer (rare). Rule out the sensor and its wiring first.
Typical fixes
- Check the sensor’s plug and wiring for damage and corrosion, where they can be reached.
- Have the sensor and its circuit tested as the service information describes, and replace the sensor if it’s faulty.
- Until it’s fixed, use the fuel grade your handbook asks for and avoid heavy loads.
- Clear the code after the repair and check that it stays away.
Questions
Can I drive with P0325?
Gently, for a short time, and have it checked soon. The engine computer can’t hear knocking now, and knocking under heavy load can damage the engine. Avoid hard acceleration and heavy loads, use the fuel grade your handbook asks for, and if you hear knocking or pinging, stop when it’s safe to do so.
Does P0325 mean my engine is knocking?
No. It means the sensor can’t report knocking, not that the engine is knocking. Without it the engine computer usually plays safe and retards the ignition.