2023 Hyundai Elantra Kona P250C Oil Level Sensor Warning

Hyundai Technical Service Bulletin 23-EM-004H addresses a warning lamp illumination for DTC P250C, 'Engine Oil Level Sensor Circuit Low,' in certain 2023 Hyundai Elantra (CN7) and Kona (OS) vehicles with the 2.0L Nu Atkinson engine. An ECU update is required to resolve the issue.

Sarah Mitchell2023 Hyundai ElantraApril 25, 2026

Certain 2023 Hyundai Elantra (CN7) and Kona (OS) vehicles equipped with the 2.0L Nu Atkinson engine may experience a warning lamp illumination related to the oil level sensor circuit. This issue is addressed by Hyundai Technical Service Bulletin (TSB) 23-EM-004H, which outlines a procedure to update the Powertrain Control Module (PCM) software.

Symptoms

Owners of affected 2023 Hyundai Elantra or Kona vehicles may notice a warning lamp illuminating on the dashboard. This light indicates a potential issue with the engine oil level sensor system.

Fault Codes / DTCs

The primary diagnostic trouble code (DTC) associated with this issue is P250C. This code specifically points to a problem within the oil level sensor circuit.

Code	Description
P250C	"Engine Oil Level Sensor Circuit Low"

Diagnosis / Trigger Conditions

The warning lamp and DTC P250C are triggered by a software logic issue within the Powertrain Control Module (PCM) concerning the oil level sensor circuit. This is not necessarily due to a faulty sensor or low oil level, but rather how the PCM interprets the sensor's readings.

Repair Procedure Summary

The resolution for the 2023 Hyundai Elantra P250C issue involves reprogramming the Powertrain Control Module (PCM) with updated software. This process is typically performed using the Global Diagnostic System (GDS) and involves several key steps:

The ECU update must initially be performed in Auto Mode via the GDS. Technicians verify the ECU ROM ID before proceeding with the software update.
If the update fails in Auto Mode, it should then be attempted in Manual Mode.
After the update reaches 100% completion, the ignition key must be cycled to the OFF position for at least 10 seconds to reset the control unit.
Following the reset, an All Systems Fault Code search is performed, and any historical DTCs that may have occurred during the update process are cleared.
Finally, the vehicle is started to confirm proper operation and ensure the warning lamp does not reappear.

Hyundai TSB 23-EM-004H also includes requirements for repair validation photos, which technicians must take and upload to the STUI system.

Required Tools or Parts

Technicians will utilize the Global Diagnostic System (GDS) for the ECU update. For additional information regarding tablet-based Mobile GDS ECU updates, TSB 15-GI-001 is referenced. The bulletin also specifies various ECU part numbers and corresponding old and new ROM IDs for both Elantra (Event #1009) and Kona (Event #1010) models, which are used to ensure the correct software is applied.

Important Warnings

Owners should be aware of specific conditions during the ECU update process:

Low Battery Voltage: If the GDS displays a

Frequently Asked Questions

What does the P250C code mean for my 2023 Hyundai Elantra or Kona?

The P250C code, or "Engine Oil Level Sensor Circuit Low," indicates a software-related issue within your vehicle's Powertrain Control Module (PCM) that affects how it interprets the oil level sensor. It typically triggers a warning light on your dashboard.

How is the Hyundai Elantra P250C issue resolved?

The issue is resolved by an ECU (Engine Control Unit) software update to the Powertrain Control Module (PCM). This update, outlined in Hyundai TSB 23-EM-004H, corrects the logic for the oil level sensor warning light.

Is TSB 23-EM-004H a recall?

No, TSB 23-EM-004H is a Technical Service Bulletin, not a recall. It provides guidance to dealerships on how to address a known issue (DTC P250C) that may arise in certain vehicles. While it addresses a potential problem, it is not a safety recall initiated by NHTSA.

What should I do if my 2023 Hyundai Elantra or Kona shows an oil level sensor warning light?

If your 2023 Hyundai Elantra or Kona displays a warning light related to the oil level sensor, especially with a DTC P250C, you should contact your authorized Hyundai dealership. They can perform the necessary ECU update as described in TSB 23-EM-004H to resolve the issue.