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P0327: Knock Sensor 1 Circuit Low Input (Bank 1)
Severity: Medium Avoid hard acceleration and heavy engine loads until diagnosed. If there is loud knocking, an oil-pressure warning, or overheating, stop the engine and arrange inspection rather than continuing to drive.
What does P0327 mean?
Knock sensor 1 on bank 1 produces less signal than the computer expects. A loose mounting, short to ground, or failed sensor can leave the engine without reliable knock feedback.
Generic OBD-II definition: Knock Sensor 1 Circuit Low Input (Bank 1). Confirm applicability in your vehicle service information.
Common causes
- Loose or incorrectly tightened sensor
- Signal shorted to ground or poor contact
- Failed knock sensor
Symptoms
- Check engine light
- Hesitation or reduced power
- Possible pinging or unusual engine noise
Diagnostic focus
Do not tighten a knock sensor by feel. Mounting torque affects how vibration reaches the sensing element, and overtightening can damage it.
Can I keep driving with P0327?
Severity: Medium Avoid hard acceleration and heavy engine loads until diagnosed. If there is loud knocking, an oil-pressure warning, or overheating, stop the engine and arrange inspection rather than continuing to drive.
If the check engine light is flashing or the car runs badly, stop driving and have it checked.
Typical fixes
- Verify mounting torque from the service manual
- Inspect the signal and any shielded wiring
- Test the circuit before replacing the sensor
Related codes
Knock Sensor 1 Circuit (Bank 1 or Single Sensor)P0326
Knock Sensor 1 Circuit Range/Performance (Bank 1)P0328
Knock Sensor 1 Circuit High Input (Bank 1)P0330
Knock Sensor 2 Circuit Malfunction (Bank 2)P0331
Knock Sensor 2 Circuit Range/Performance (Bank 2)P0332
Knock Sensor 2 Circuit Low Input (Bank 2)
Sources & review
Definitions and diagnostic background checked 2026-11-06. Generic guidance, not a substitute for the service procedure for your exact year, engine, and transmission.