P0325
Knock Sensor 1 Circuit Malfunction (Bank 1)
A general fault has been detected in the bank 1 knock sensor circuit. The ECU uses the knock sensor to detect pre-ignition and retards ignition timing when knock occurs; with no signal, the ECU runs conservative timing and loses power.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Symptoms
- Check engine light on
- Power loss from defensive spark retard
- Increased fuel consumption
- Possible audible pinging under load
Common causes
Ordered by how often each turns out to be the cause.
- Knock sensor failedCommon
- Sensor mounting bolt loose (sensor must be torqued correctly)Possible
- Wiring faultLess likely
Parts involved
- Knock Sensor
- Knock Sensor Wiring
P0325 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.