P0325 Knock Sensor 1 Circuit Malfunction (Bank 1 or Single Sensor)

P0325 points to a knock-sensor circuit malfunction for bank 1 or a single-sensor setup. It is usually an input-circuit problem, not proof that the engine is actually knocking.

Code status

Needs verification

Not yet verified against SAE J2012_202509 / J2012DA. Treat unverified rows as a lookup aid, not repair authority.

System: Ignition / Misfire
Scope: iso-sae-controlled-p0
Standard: SAE J2012 / ISO 15031-6
Source: legacy-import

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not tune around or ignore a knock-sensor circuit fault; the control module may lose important detonation protection.

Useful checks before replacing parts

Inspect knock-sensor wiring, connector condition, shielding, routing, and sensor torque or mounting if service information calls for it.
Check for water intrusion, rodent damage, or harness repairs in the valley or under-intake area on engines where the sensor is buried.
Review timing, fuel quality, and companion codes only after the sensor circuit is proven sound.

Related OBD-II codes

These nearby ignition / misfire entries can help compare wording and fault area. They may share the same verification status as the source database.