P0326: Knock/Combustion Vibration Sensor A Circuit Range/Performance

A generic powertrain (engine and transmission) trouble code, same meaning on every brand.

Fix within weeks

Yes - the computer retards timing to protect the engine, so expect less power.

$80 - $600

typical repair range

NHTSA complaints mention this code

97,000

median mileage when reported, mi

Symptoms

Reduced power, especially uphill
Slightly worse economy
Occasional pinging under load

Likely causes, most common first

Knock sensor failing or loose
Wiring or connector fault
Genuine engine noise from a mechanical problem
Incorrect torque on the sensor mounting bolt

Read P0326 yourself before paying for diagnosis

A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.

What is going on and how it gets diagnosed

P0326 means the knock sensor signal is present but does not look the way the computer expects. Knock sensors are microphones bolted to the engine block that listen for the sharp rattle of detonation, and their mounting torque matters - a loose sensor hears the wrong things.

Take seriously the possibility that the sensor is right. A worn connecting rod bearing or a loose accessory produces noise in the same frequency band as detonation, and a code that keeps returning after a good sensor has been fitted deserves a mechanical inspection rather than another sensor.

Repair options and cost

Knock sensor$200 - $600

Wiring repair$80 - $250

Mechanical noise diagnosis$120 - $250

Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.

Owner reports mentioning P0326

“Brandâ'new 2026 Nissan Armada suffered catastrophic engine failure at under 5,000 miles. Fault codes P21A1, P0019, P0326, and P219C were identified by an ASE Master Technician. Technician warned of internal mechanical failure and a risk of fire or explosion. Vehicle became undriveable and was towed to the dealership. Technician instructed that the engine should not be started due to safety risk.”NHTSA complaint · Apr 2026

“The contact owns a 2014 Kia Optima. The contact stated while driving at approximately 35 MPH, the vehicle stalled and restarted. The check engine warning light was blinking. The vehicle was taken to an independent mechanic, who determined that the failure was due to DTC Code: P0326 Knock Sensor (1 Circuit Range Performance Bank 1). The vehicle was towed to the local dealer, who informed the contact that there was no recall coverage for the failure. The vehicle was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was approximately 217,581.”2014 Kia Optima · Jul 2024 · 217,581 mi

“UNKNOWN FULLY Engine knocking out of the blue and then died. Car went limp while driving down the road. Starts and is loudly knocking. Throws codes P0011 and P0326 Cannot drive vehicle. I have not notified hyundai yet. There were no warning lights. Car ran perfectly fine. No issues. Then the engine just died.”2016 Hyundai Tucson · Oct 2023

Show 6 more owner reports

“I bought my 2010 GMC Terrain SLE at 160,000. It had a rough start up but the dealer said it was because it was an older car and been sitting for a while. The rough start up never stopped even after replacing the catalytic converter because of code P0420. The mechanic informed of this specific vehicle oil composition so I was consistently checking the oil. A month after the NEW catalytic converter was installed. I stalled out on the interstate with traffic going 65 mph minimum, the wheel locked and I was almost rear ended. I take the vehicle to an automotive shop and I need a new timing chain with numerous new codes. P0325 P0326 P0327 P0016 P0017 P0014.”2010 GMC Terrain · Nov 2021

“While driving on the freeway (70mph) , the engine began to knock and shake the car. Then there was a bang, and several puffs of white smoke, and the car died. We had it towed to the shop, and they told us that a piston shot through the bottom of the engine block, and drained all the oil in the car. The entire engine would need to be replaced. Quoted cost to repair 9k for a used engine, 15k for a new engine. The car was well maintained, and serviced regularly.*dt consumer stated following codes from diagnostic p0326, p0014 p0303.*jb*dt consumer statedmanufacturer could not do anything about.*jb”2016 Kia Soul · Oct 2020 · 108,307 mi

“Driving to work from lunch my car stalled and then completely stopped in the middle of the road. The engine light started flashing and then my car started to move again but it was sluggish and slow. It wont go past 45 miles before slowing all the way down. I had got my car recalled three days before, they said nothing was wrong with the engine/transmission at the time of the recall. Now three day later my cars stuck in limp mode showing a p0326 code.”2016 Kia Soul · Mar 2020 · 57,568 mi

“Once I am driving on the highway the car seems to loose power almost like if the car wants to shut off the rmp goes low then the check engine light has turned on. I have taken it for its service on time and no issues but the good year rep told me the error code they received was p0326 which is the knock sensor and now the engine light went away but it has happened twice so far within the last two months.”2013 Hyundai Accent · Jan 2019 · 79,000 mi

“As I go up a hill or rapidly accelerate on an incline the check engine light will come on. The problem points to the knock sensor (code p0326) being at fault. This does not happen often but when it does it is disconcerting. I replaced the knock sensor with a new oem part, but it too acts the same as the old one. I called the dealer and they want to charge me $90 to diagnose the problem and then any labor/parts needed to repair it. However, I have read several reports online about a software update, flashing the ecu has fixed the problem. If this is so, shouldn't this be a reason for a recall?”2013 Hyundai Accent · Aug 2018 · 97,000 mi

“While drive about 60 mph the check engine light came on (02/20/2018). I went to get the codes read by a local auto parts store. The codes p050a and p0326 were identified. I have had many issues with the check engine light coming on with the same codes. When I make an appointment to get it checked out. The check engine light goes off. I have just had my vehicle inspected and emission test completed by the #1 cochran hyundai dealership (monroeville, pa) on 02/16/2018. This seems to be a continuous issue. Check engine light comes on for maybe a week or so then goes off for a week or so.”2012 Hyundai Accent · Feb 2018 · 76,530 mi

Cars that report P0326 most often

Based on mentions of this code in NHTSA owner complaints.

Frequently asked questions

Can I drive with P0326?

Yes - the computer retards timing to protect the engine, so expect less power.

How much does it cost to fix P0326?

Typical US repair costs range from $80 for the simplest fix (knock sensor) to $600 in the worst case. The right number depends on which cause your car has - see the causes list.

Related codes

The codes closest to P0326. They often appear together, and telling them apart is usually what narrows the diagnosis.

P0320Ignition/Distributor Engine Speed Input Circuit P0325Knock/Combustion Vibration Sensor A Circuit P0327Knock/Combustion Vibration Sensor A Circuit Low P0300Random/Multiple Cylinder Misfire Detected P0301Cylinder 1 Misfire Detected P0302Cylinder 2 Misfire Detected P0303Cylinder 3 Misfire Detected P0304Cylinder 4 Misfire Detected

Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.