P0327🔧 Knock sensor / ignition timingDrive with caution, fix soon

P0327: Knock Sensor 1 Circuit Low, Bank 1 (Meaning, Causes, Fixes)

Reviewed 2026-10-22 · Based on 2 cited source(s)

What P0327 means

A knock sensor is a small sensor bolted to the engine that listens for knocking or pinging, which is fuel burning in the cylinders the wrong way. When it hears knock, the engine computer retards (delays) the ignition timing until the knock stops. P0327 sets when the signal from the bank 1 knock sensor circuit is lower than its normal range. OBD-Codes.com gives an example of a low output under about 0.5 volts and says the code may come and go or the light may stay on. RepairPal explains that the computer may treat it as an irrational reading when timing has been advanced a lot and the sensor still reports no knock. It is a generic OBD-II code, so it applies to most 1996 and newer vehicles, though repair steps vary by make and model. OBD-Codes.com lists related knock sensor codes P0325 to P0334.

Severity: can I keep driving?

Drive with caution, fix soon

Get it checked soon, but it's usually not an emergency. RepairPal rates P0327 Moderate, meaning it may not threaten safety right away but should be diagnosed within a reasonable time. A knock sensor that isn't reporting means the engine computer may not catch pinging (knock), which can damage the engine if it goes on. If you hear pinging or knocking, the engine runs hotter than normal, or it loses power, ease off hard acceleration and get it looked at promptly. If the temperature gauge climbs toward hot, pull over and shut the engine off.

Common symptoms

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

  1. Faulty knock sensor (both sources)
  2. Open, shorted or damaged wiring or poor connections in the knock sensor circuit (both sources)
  3. A failed engine computer (PCM/ECM) (OBD-Codes.com)
  4. EGR system problem (RepairPal only)
  5. Cooling system problem (RepairPal only)
  6. Rich air/fuel mixture (RepairPal only)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

  1. Check the coolant level and condition and the engine oil level, as RepairPal suggests, to rule out a mechanical or cooling problem first.
  2. Inspect the wiring and connector going to the knock sensor for broken, frayed or chafed wires and corrosion. OBD-Codes.com recommends checking the connections all the way to the engine computer.
  3. If you have a multimeter and a service manual, check the sensor's resistance and the circuit's ground and voltage against the factory specs, as OBD-Codes.com suggests.
  4. Write down the freeze frame data from your scanner so a shop knows the conditions when the code set.

Typical fixes

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

  • You hear pinging or knocking, or the engine is running hot
  • The knock sensor is hard to reach; on some engines it sits under the intake manifold
  • The code returns after a new sensor; RepairPal says common misdiagnoses are replacing the knock sensor when the real cause was the cooling system or the EGR system
  • You can't test the circuit with a scan tool that shows live knock sensor and timing advance data

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Is P0327 serious?

RepairPal rates it Moderate. It usually isn't an emergency, but if the knock sensor isn't working the engine computer may not catch knocking, which can damage the engine over time. Get it diagnosed soon.

Can I drive with P0327?

Usually yes for normal driving to a shop, if the engine runs smoothly. Avoid hard acceleration and heavy loads, and stop if you hear knocking or the engine overheats.

Will a new knock sensor fix P0327?

Often, but not always. RepairPal says sensors are sometimes replaced when the real cause was a cooling system or EGR problem, and OBD-Codes.com lists wiring faults as a common cause. Check the wiring and the engine first.

How much does it cost to fix P0327?

Neither source gives a repair cost. It depends on whether the fix is wiring, the sensor itself, or another engine problem, and on how hard the sensor is to reach, so get a diagnosis and written estimate first.

Sources

  1. OBD-Codes.com: P0327 Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor)
  2. RepairPal: P0327 Knock Sensor 1 Circuit Low (rated Moderate)

Last reviewed 2026-10-22. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.