P0325 on Kia: How to Diagnose & Fix
Knock Sensor 1 Circuit Malfunction (Bank 1)
2 Kia models · 2 documented issues · 1 critical
P0325 on Kia by model: symptoms, diagnosis and fix
The Theta II 2.4L and 2.0T GDI engines in 2011-2019 Sorentos can experience catastrophic engine seizure due to machining debris left in the crankshaft oil passages during manufacturing. Metal shavings restrict oil flow to rod and main bearings, causing premature bearing wear and eventual engine lock-up. Over 340,000 Sorentos were included in NHTSA Recall 17V-224. Kia extended the powertrain warranty to 10 years/120,000 miles for affected vehicles and deployed the Knock Sensor Detection System (KSDS) software update to detect early bearing deterioration.
Common Symptoms
- Engine knocking or ticking noise that worsens over time
- Oil pressure warning light illuminated
- Metal shavings found in oil during changes
- Sudden engine stall while driving
- Excessive oil consumption (more than 1 qt per 1,000 miles)
- Check engine light with bearing-related codes
How to Fix
Check VIN eligibility for extended warranty (10 years/120,000 miles). Have dealer perform KSDS software update to detect early bearing failure. If engine is knocking, dealer will perform oil consumption test and bearing inspection. Complete engine replacement required if bearings are scored. Dealer replaces with updated long block assembly under warranty if eligible.
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Owner tips & cautions
- WarningIf you hear any knocking, stop driving immediately. Continued operation with failing bearings causes catastrophic damage that may not be covered if engine locks up completely
- TipCheck your VIN at owners.kia.com/recalls - even if past the original warranty, the extended 10yr/120k warranty applies to Theta II bearing failures
- TipUse 0W-20 full synthetic oil and change every 5,000 miles to maximize bearing life. Pennzoil Platinum or Mobil 1 are frequently recommended on KiaForums
Sources for this issue (3)
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.
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.
P0325 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 P0325 mean on a Kia?
P0325 stands for "Knock Sensor 1 Circuit Malfunction (Bank 1)." This code indicates a fault in the knock sensor 1 circuit on Bank 1. The knock sensor listens for the vibrations of detonation (pinging/spark knock) and lets the computer retard ignition timing to protect the engine. When the sensor's signal is missing, out of range, or the circuit is open/shorted, P0325 sets. With knock detection compromised, the computer may run more conservative timing, causing reduced power and slightly lower fuel economy, and the engine is less protected against damaging knock. On Kia it is documented across 2 models: Sorento, K5.
What are the most common causes of P0325?
The most common causes of P0325 are: Failed knock sensor, Corroded or loose knock sensor connector, Damaged, open, or shorted sensor wiring, Improperly torqued or loosely mounted sensor, Moisture or corrosion in the connector, Wiring harness chafing near the engine, Faulty PCM/ECM (rare). The specific cause varies by vehicle.
How much does it cost to fix P0325 on a Kia?
Repair costs vary widely with the root cause and Kia model; each issue on this page carries its own estimate where one is published.
Looking for P0325 on a different make?
View P0325 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.