P0327

Universal

Knock Sensor 1 Circuit low Input (Bank 2 or Single Sensor)

Definition source: General OBD-II reference catalog

Definition verification: Not independently verified for display.

Time: Varies by diagnosis and vehicle | Diagnostic difficulty: Medium

Medium Severity

The engine computer monitors Knock Sensor 1 for vibrations associated with engine knock. This code means the signal from that sensor circuit is lower than expected. The cause could be the sensor or its wiring and connections; the code alone does not prove the sensor has failed. Depending on the vehicle, engine control may adjust timing, and performance or fuel economy may be affected.

Report an error with this code

⚠️ Before You Begin (Safety First)

If you hear persistent metallic knocking or pinging, avoid hard acceleration and heavy engine loads, and arrange a prompt inspection. Stop driving if the engine runs severely rough, loses power suddenly, or shows signs of overheating. The code does not by itself confirm that the engine is knocking.

Common Symptoms

The check-engine light may be on, sometimes with no noticeable change in how the vehicle runs.
Reduced power or slower acceleration may occur if engine control adjusts timing in response to the fault.
Fuel economy may worsen if engine control cannot use knock information as intended.
Engine pinging or knocking may be noticed, but this code does not establish that actual engine knock is occurring.
Some vehicles may have no obvious symptoms.

Common Causes

Knock Sensor 1 may have an internal fault that produces a low signal.
Damaged, corroded, loose, or poorly connected wiring or terminals may reduce the signal reaching the engine computer.
A wiring fault, including an unintended short to ground, may pull the circuit signal low.
A fault in the engine computer or its circuit may be possible after the sensor and wiring have been checked.

Diagnostic Steps

Check whether the engine has persistent knocking, severe rough running, sudden power loss, or overheating; avoid driving under heavy load and seek service if these occur.
With the engine off and cool, visually inspect accessible knock-sensor wiring and connectors for damage, looseness, corrosion, or contamination. Do not reach near hot or moving parts.
Confirm the vehicle's engine configuration and sensor location using model-, year-, and engine-specific service information; the definition allows Bank 2 or a single-sensor arrangement.
If the code returns or the connector and wiring are not clearly intact, have the circuit tested before replacing the sensor. Avoid probing terminals unless the correct procedure and tools are available.

When to Call a Professional

A technician can review scan data and freeze-frame information, inspect the sensor circuit and connector, and test the sensor signal and wiring using model-specific service information. Confirm the fault is in the sensor circuit before replacing parts; the sensor location and test procedure vary by engine.

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Commonly Asked Questions

Does P0327 prove the knock sensor is bad?

No. It identifies a low signal in the Knock Sensor 1 circuit. The sensor, wiring, connector, or another circuit fault could be responsible.

Does this code mean the engine is actually knocking?

Not necessarily. It reports a low sensor-circuit input, not confirmed engine knock. Persistent audible knocking should still be checked promptly.

What does Bank 2 or Single Sensor mean here?

The sensor designation depends on the engine configuration. This definition covers Knock Sensor 1 on Bank 2 or a single-sensor arrangement; the vehicle's service information is needed to identify the applicable setup.

Can I keep driving with P0327?

If the vehicle runs normally and there is no persistent knocking, severe roughness, sudden power loss, or overheating, arrange diagnosis soon and avoid heavy engine loads. Stop driving and seek help if serious symptoms occur.

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