P0325 on a 2022 Hyundai Elantra
Knock Sensor 1 Circuit Fault
P0325 on a 2022 Hyundai Elantra indicates knock sensor 1 circuit fault. It usually stays drivable short-term but should be diagnosed promptly. The most common cause is failed knock sensor element (typically $150–$600). Confirm the root cause before replacing parts.
What does P0325 mean on a 2022 Hyundai Elantra?
P0325 is set when the engine control module does not receive a valid signal from the Bank 1 knock sensor — or the only knock sensor on engines that use one. The knock sensor is a piezoelectric vibration sensor that listens for the characteristic frequency of pre-ignition (detonation) so the ECM can pull timing to protect the engine. With no usable knock signal, the ECM defaults to conservative timing maps, which reduces power and fuel economy.
This guide covers P0325 across the 2020-2024 Hyundai Elantra generation — the symptoms, causes, and diagnostic steps below apply to every model year from 2020 through 2024.
Is it safe to drive a 2022 Hyundai Elantra with P0325?
In most cases a 2022 Hyundai Elantra stays drivable for short trips with P0325 active, but diagnose and repair it promptly. This is a moderate-severity code — ignoring it can lead to further damage or a failed emissions test.
What are the symptoms of P0325 on a 2022 Hyundai Elantra?
- Check Engine Light is illuminated
- Reduced power and slower throttle response
- Slight reduction in fuel economy
- Engine may run cooler than normal under load
- Possible audible engine ping or knock under hard acceleration
- No drivability issue in normal driving
What causes P0325 on a 2022 Hyundai Elantra?
| Cause | Likelihood | Estimated repair (USD) |
|---|---|---|
| Failed knock sensor element Most common at 100k+ miles. Some engines bury the sensor under the intake. | Most common | $150–$600 |
| Damaged or corroded knock sensor wiring or connector | Common | $80–$350 |
| Loose knock sensor mounting (sensor must be torqued correctly to "hear") | Common | $20–$100 |
| Rodent damage to knock sensor harness (parked vehicles) | Occasional | $80–$350 |
| Failed knock sensor sub-harness on GM L83/L86 truck V8s Specific to GM 5.3 / 6.2 truck V8s — well-documented sub-harness failure. | Occasional | $200–$600 |
| Internal engine damage producing noise outside the knock sensor band | Rare | $2,000–$6,000 |
How to diagnose this on a 2022 Hyundai Elantra
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Locate the knock sensor — often under the intake manifold
On many engines (notably GM V6 + V8 truck engines, Toyota 2GR-FE, and most modern Hondas) the knock sensor sits in the engine valley under the intake manifold. Knowing this before starting saves a wasted hour of looking. Consult the service manual.
Tools: Vehicle-specific service information
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Test knock sensor resistance
Unplug the sensor and measure resistance with a multimeter. Most knock sensors read approximately 90 kΩ to 2.5 MΩ depending on style. Infinite resistance (open) or near-zero (short) confirms a failed sensor.
Tools: Multimeter, Service spec sheet
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Inspect the wiring and connector
Knock sensor harnesses run close to hot exhaust components and are common chafing victims. Inspect every inch of the harness from the sensor to the PCM connector. Repair any visible damage before replacing the sensor.
Tools: Inspection mirror, Flashlight, Wire repair supplies
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Verify torque specification on the existing sensor
A knock sensor mounted with the wrong torque cannot transmit vibration efficiently. Spec is typically 15–25 ft-lb. Use a torque wrench, not "tight by feel." Over-torque can crack the housing; under-torque produces false knock-sensor codes.
Tools: Torque wrench, Service spec sheet
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Check for GM-specific sub-harness failure
On GM L83 (5.3 V8) and L86 (6.2 V8) truck engines, the knock sensor sub-harness running under the intake manifold is a documented failure point — the harness chafes and shorts. Replacement requires intake manifold removal. The sub-harness itself is inexpensive but the labor is significant.
Tools: Intake manifold gasket, Common hand tools
NHTSA complaints & recalls for the 2022 Hyundai Elantra
Owner-reported safety complaints and official recalls filed with the U.S. National Highway Traffic Safety Administration for the 2022 Hyundai Elantra. Use these to gauge how common a problem is on your specific vehicle before you start chasing Hyundai Elantra diagnostics.
- ENGINE 10
- SEAT BELTS 23
- UNKNOWN OR OTHER 20
- ELECTRICAL SYSTEM 17
- FORWARD COLLISION AVOIDANCE 15
5 active recalls
- SEAT BELTS:FRONT Mar 2022
Hyundai Motor America (Hyundai) is recalling certain 2022 Elantra and Elantra HEV vehicles. In the event of a crash, the front passenger-side seat belt pretensioner may explode upon deployment.…
NHTSA campaign 22V123000 - SEAT BELTS:FRONT Apr 2022
Hyundai Motor America (Hyundai) is recalling certain 2021-2022 Elantra and 2020 Accent vehicles. In the event of a crash, the front driver and passenger-side seat belt pretensioners may explode upon deployment.…
NHTSA campaign 22V218000 - SEAT BELTS:FRONT May 2022
Hyundai Motor America (Hyundai) is recalling certain 2020-2022 Accent, 2021-2022 Elantra, and 2021-2022 Elantra HEV vehicles. In the event of a crash, the front driver-side and/or passenger-side seat belt pretensioners may explode upon deployment.…
NHTSA campaign 22V354000 - AIR BAGS:FRONTAL Aug 2022
Hyundai Motor America (Hyundai) is recalling certain 2022 Elantra N and 2022-2023 Elantra vehicles. The emblem on the cover of the driver's front air bag may not have been welded properly, which can result in the emblem detaching upon deployment.…
NHTSA campaign 22V632000
How do I fix P0325 on a 2022 Hyundai Elantra?
- Replace the knock sensor with an OEM part
- Replace the knock sensor sub-harness (GM L83/L86)
- Repair damaged wiring to the knock sensor
- Re-torque the sensor to OEM specification
About the 2020-2024 Hyundai Elantra
The 2020-2024 Hyundai Elantra was commonly sold with the following powertrains: 2.0L I4, 1.6L Turbo I4, 1.6L Hybrid I4. Common trims include SE, SEL, N Line, Limited.
Why P0325 is a “common” code on GM V8 trucks
GM L83 (5.3L) and L86 (6.2L) Gen V V8 engines — used in 2014+ Silverado, Sierra, Tahoe, Yukon, Suburban, and Escalade — have a well-documented knock sensor sub-harness failure. The harness chafes against the intake valley pan and eventually shorts. P0325 + P0330 setting together on these engines is so common that aftermarket “extended” sub-harnesses are sold specifically to relocate the wiring away from the chafe point.
If you have one of these vehicles, expect this repair around 80–130k miles. Plan it with the next intake manifold service.
What the ECM does without a working knock sensor
The engine still runs — but conservatively. The ECM uses “open-loop” ignition timing maps that pull 3–6 degrees of advance out of every cell, sacrificing power and fuel economy to ensure no detonation. Expect 1–2 MPG lower and noticeably slower throttle response.
Knock sensor diagnostics with a scope
The knock sensor is essentially a microphone. Tapping the cylinder block near the sensor with a screwdriver while watching the scan-tool knock count PID should produce hits. No response to tapping confirms a dead sensor or open wiring even if the multimeter resistance looks correct.