P0326 on 2021-2025 Kia K5 — Knock Sensor 1 Circuit Range/Performance (Bank 1 or Single Sensor)
1 vehicles · 1 makes
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Kia K5 · 2021–2025
The 2.5L Theta II engine in certain K5 models has experienced knock sensor faults and engine knock concerns. The knock sensor may trigger false positives or fail to detect actual detonation, causing the ECU to either retard timing unnecessarily (reducing power) or fail to protect against harmful knock. Kia issued a software update to improve knock detection logic, but some owners report persistent issues after the update.
Common Symptoms
- Check engine light with knock sensor codes
- Reduced engine power or sluggish acceleration
- Audible pinging or knocking under load
- Poor fuel economy from excessive timing retard
- Engine hesitation during acceleration
How to Fix
Visit a Kia dealer for the latest ECU software update (TSB SA508) that improves knock detection calibration — this is typically performed at no cost. If the knock sensor itself has failed, replacement costs $200-$400 including labor. Use only 87+ octane fuel as specified. If actual engine knock is present (metallic pinging under load), have the engine inspected immediately as the Theta II engine family has a known history of connecting rod bearing issues in earlier applications. Kia has extended warranty coverage on some Theta II engines.
Call to confirm they can assess your vehicle and perform the stated work. Search results do not confirm qualification, eligibility or coverage.
Owner tips & cautions
- TipCheck if your VIN is covered under the Kia engine warranty extension. Many Theta II engines have extended coverage to 150,000 miles for knock-related failures.
- TipRequest the latest ECU calibration update at every service visit. Kia has released multiple updates to improve knock detection and engine protection logic.
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P0326 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0326 mean?
P0326 stands for "Knock Sensor 1 Circuit Range/Performance (Bank 1 or Single Sensor)." P0326 is a generic powertrain code indicating the engine computer detected that the knock sensor 1 (bank 1) signal is outside its expected range or performing improperly. The knock sensor listens for engine 'knock' (pre-ignition/detonation) so the PCM can retard timing to protect the engine; an out-of-range signal means the computer can no longer rely on it. This usually causes reduced performance and fuel economy and, if knock goes undetected, possible long-term engine wear.
What are the most common causes of P0326?
The most common causes of P0326 are: Faulty knock sensor, Damaged knock sensor wiring or connector, Corrosion or poor contact at the sensor, Engine mechanical noise mimicking knock, Loose sensor mounting / incorrect torque, Wiring shorted or open to the PCM, PCM fault (rare). The specific cause varies by vehicle.
How much does it cost to fix P0326?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by P0326?
Au7o has documented P0326 across 1 vehicle models from 1 manufacturers: Kia.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.