Defective knock sensor (both sources). Knock sensor wiring or connector problems, such as burnt, corroded or broken wires (both sources). PCM failure or a PCM programming error (both sources). Internal engine malfunction (OBD-Codes.com). Ignition misfires (OBD-Codes.com). Contaminated or substandard fuel (OBD-Codes.com).

Repair damaged knock sensor wiring or connectors. Replace the knock sensor once testing confirms it has failed (RepairPal lists knock sensor replacement as the common repair). Fix any misfire or internal engine noise found first (OBD-Codes.com). Repair or reprogram the PCM if it is confirmed faulty, which is less common.

P0324🔧 Engine / ignition (knock sensor control)Drive with caution, fix soon

P0324: Knock Control System Error (Meaning, Causes, Fixes)

Q: What does P0324 mean?

P0324 means the engine computer found a problem in the knock control system, the knock sensor, its wiring and the computer that reads it. A failed knock sensor or damaged wiring is the most common cause, but OBD-Codes.com warns it can also point to a real internal engine problem. The knock sensor is a small piezoelectric sensor, usually threaded into the engine block or mounted under the intake manifold, that produces a small voltage when the engine vibrates. The powertrain control module (PCM) uses that signal to detect knock (pinging) and pull back ignition timing to protect the engine. OBD-Codes.com explains that the PCM stores P0324 when it sees an unexpected signal from the knock sensor, such as battery voltage, a complete short to ground or a pulsing voltage, and notes that a very severe engine noise (for example a connecting rod hitting the block) can also set a knock sensor code. RepairPal describes the trigger more narrowly: it says the PCM sets P0324 when it does not receive a signal from the knock sensor, and that the check engine light may or may not come on. Both point to the same system. Related knock sensor codes include P0325 through P0334.

Q: Can I keep driving with P0324?

Drive with caution, fix soon. Get it checked soon, and treat it as urgent if the engine is noisy. Sources differ on how serious it is: RepairPal rates P0324 Moderate, meaning it may not threaten safety right away but should be diagnosed within a reasonable time, while OBD-Codes.com says it could be a sign of severe internal engine failure and must be addressed with some degree of urgency. If you hear loud knocking or banging from the engine, or it loses power, stop driving hard and have it inspected before driving much further. A quiet engine with only the light on is usually a sensor or wiring issue, but get it diagnosed.

Reviewed 2026-10-23 · Based on 2 cited source(s)

What P0324 means

The knock sensor is a small piezoelectric sensor, usually threaded into the engine block or mounted under the intake manifold, that produces a small voltage when the engine vibrates. The powertrain control module (PCM) uses that signal to detect knock (pinging) and pull back ignition timing to protect the engine. OBD-Codes.com explains that the PCM stores P0324 when it sees an unexpected signal from the knock sensor, such as battery voltage, a complete short to ground or a pulsing voltage, and notes that a very severe engine noise (for example a connecting rod hitting the block) can also set a knock sensor code. RepairPal describes the trigger more narrowly: it says the PCM sets P0324 when it does not receive a signal from the knock sensor, and that the check engine light may or may not come on. Both point to the same system. Related knock sensor codes include P0325 through P0334.

Severity: can I keep driving?

Drive with caution, fix soon

Get it checked soon, and treat it as urgent if the engine is noisy. Sources differ on how serious it is: RepairPal rates P0324 Moderate, meaning it may not threaten safety right away but should be diagnosed within a reasonable time, while OBD-Codes.com says it could be a sign of severe internal engine failure and must be addressed with some degree of urgency. If you hear loud knocking or banging from the engine, or it loses power, stop driving hard and have it inspected before driving much further. A quiet engine with only the light on is usually a sensor or wiring issue, but get it diagnosed.

Common symptoms

Check engine light on (RepairPal says it may or may not be lit)
Diminished engine performance (OBD-Codes.com)
Hesitation when accelerating (OBD-Codes.com)
Loud noises from the engine area (OBD-Codes.com)
Decreased fuel efficiency (OBD-Codes.com)

Likely causes

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

Defective knock sensor (both sources)
Knock sensor wiring or connector problems, such as burnt, corroded or broken wires (both sources)
PCM failure or a PCM programming error (both sources)
Internal engine malfunction (OBD-Codes.com)
Ignition misfires (OBD-Codes.com)
Contaminated or substandard fuel (OBD-Codes.com)

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.

Listen to the engine first. OBD-Codes.com says that if the engine is knocking or unusually noisy in any way, fix that before chasing the knock sensor code.
Read all stored codes and freeze frame data, then clear the codes and test drive to see whether P0324 comes back.
Visually inspect the knock sensor wiring and connectors for burnt, corroded or broken wires. OBD-Codes.com notes that sensors low on the block are often damaged when nearby parts like the starter or engine mounts are replaced, so think about recent repairs.
Use only good-quality fuel from a reputable station if you suspect bad fuel.

Typical fixes

Repair damaged knock sensor wiring or connectors
Replace the knock sensor once testing confirms it has failed (RepairPal lists knock sensor replacement as the common repair)
Fix any misfire or internal engine noise found first (OBD-Codes.com)
Repair or reprogram the PCM if it is confirmed faulty, which is less common

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

The engine is knocking, banging or making loud noises, which can mean internal damage
Testing knock sensor voltage needs a scan tool, a digital volt/ohmmeter and the manufacturer's specifications (OBD-Codes.com)
The knock sensor is threaded into a coolant passage. OBD-Codes.com warns that removing it from a warm engine can spray hot coolant, so let the engine cool and drain the coolant first
OBD-Codes.com suggests checking for technical service bulletins (TSBs) that match your vehicle, code and symptoms, which a dealer or shop can look up

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

Can I drive with P0324?

Usually, for a short time, if the engine sounds normal. RepairPal rates it Moderate, but OBD-Codes.com warns it can signal severe internal engine failure, so don't drive hard and get it checked promptly, especially if you hear knocking.

Is P0324 always a bad knock sensor?

No. Both sources list wiring and PCM problems too, and OBD-Codes.com adds misfires, bad fuel and internal engine problems. OBD-Codes.com also says knock control codes are usually confined to wiring, connectors and controllers, so check the wiring before buying a sensor.

What's the difference between P0324 and P0325?

P0324 is a general knock control system error, while P0325 points at the knock sensor 1 circuit specifically. They often share the same causes; see our P0325 page.

How much does it cost to fix P0324?

Neither source gives a repair cost for P0324. It can be anything from a wiring repair to a knock sensor or, rarely, engine work, so get it diagnosed first.

Sources

Last reviewed 2026-10-23. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.