OBD codes / P0325 / Nissan Altima
P0325 on a Nissan Altima
Knock Sensor 1 Circuit Malfunction (Bank 1)
QR25 and VQ35 Altima.
What P0325 usually means on a Altima
P0325 means the Altima's knock sensor circuit has failed, so the ECU cannot detect detonation and retards timing defensively. Expect slightly reduced power or economy while it is set. On these engines the sensor sits in the engine valley or under the intake on the V6, so access can add labor. The sensor, connector, or wiring is the usual fault.
Most likely causes on this model
- Failed knock sensor
The sensor fails with age and heat, opening the circuit.
- Wiring or connector damage
The knock-sensor harness corrodes or chafes over time.
- Poor ground or ECU connection
A degraded ground mimics a bad sensor.
What it costs on a Altima
The part is modest, but on the V6 the knock sensor lives under the intake, so labor can dominate. On the four the access is friendlier. Inspect the connector and wiring first before ordering a sensor.
Year, engine and mileage change the answer. Get a diagnosis for your Altima — it weighs these causes against your exact configuration and real complaint data.
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Related symptoms
Nissan Altima problems & recalls by year
Based on widely reported patterns for this model; individual causes vary by year, engine and history. Generic P0325 behavior is covered on the main P0325 page. Confirm with a scan tool before buying parts.