P0328 Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor)

P0328 indicates a high input condition in Knock Sensor 1 circuit on Bank 1 or a single-sensor engine. The controller is seeing voltage or signal level above the expected range.

Code details

Generic OBD-II · P0

System: Ignition / Misfire
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

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 install a new knock sensor without checking for open signal wiring or poor connector contact that can create a high-input code.

Symptoms of P0328

Rough idle, shaking, or a stumble under acceleration.
A flashing check-engine light during an active misfire.
Power loss and higher fuel consumption.

Common causes of P0328

Worn spark plugs, ignition coils, or plug wires.
Fuel-delivery problems — injectors, pressure, or a lean/rich mixture.
Vacuum leaks, low compression, or a mechanical fault in that cylinder.

Useful checks before replacing parts

Check Knock Sensor 1 voltage, wiring continuity, connector condition, sensor ground path, reference behavior, and freeze-frame load when the high input set.
Inspect for open circuits, short-to-voltage faults, loose sensor mounting, corrosion, harness damage, and abnormal engine noise that can saturate the signal.
Compare KOEO and running readings with service information to separate an electrical high input from true severe knock or noise.

Related OBD-II codes

These nearby ignition / misfire entries can help compare wording and pin down the fault area.