Hyundai and Kia share many platforms, engines, and electronic systems, which means their dashboard warning lights and diagnostic approaches are very similar. This guide covers the most common warning lights across both brands and how to diagnose them.
Check Engine Light
Common triggers on Hyundai and Kia vehicles include oxygen sensor faults, catalytic converter efficiency codes (P0420), knock sensor faults (particularly on the Theta II 2.0T and 2.4L GDI engines), purge valve failures causing EVAP codes, and mass airflow sensor contamination. The Theta II engines in particular have had well-documented issues with connecting rod bearing wear that can trigger knock sensor and oil pressure codes. A flashing check engine light means active misfires – reduce speed immediately and get the vehicle scanned.
EPS Warning Light (Electric Power Steering)
Hyundai and Kia vehicles use electric power steering across their range. The EPS warning light indicates a fault in the system, which may result in heavier steering or loss of power assist. Common causes include a failing torque sensor on the steering column, an EPS motor fault, or a wiring issue. On some Hyundai i30 and Kia Cerato models, a known issue with the EPS control module can cause intermittent loss of assist. Your workshop manual includes the EPS diagnostic procedure and sensor specifications.
ESC Warning Light (Electronic Stability Control)
The ESC light flashing during slippery conditions is normal operation. If it stays on permanently, the most common cause is a wheel speed sensor fault. On Hyundai Tucson and Kia Sportage models, the rear wheel speed sensors are particularly prone to failure due to their exposed position. The workshop manual provides sensor resistance values and testing procedures for each wheel position.
DPF Warning (Diesel Models)
Hyundai and Kia diesel models (Tucson, Santa Fe, Sportage, Sorento with CRDi engines) have a DPF warning system. The light means the filter needs regeneration through sustained highway driving at 60 km/h or above for 20 to 30 minutes. If the light starts flashing, the filter is critically blocked and may require forced regeneration with a diagnostic tool. Short urban trips without allowing regeneration are the primary cause of DPF problems on these vehicles.
TPMS Warning
The tyre pressure monitoring system light illuminates when one or more tyres are significantly below the recommended pressure. Check all tyres with a gauge and inflate to the pressures on the door jamb placard. On Hyundai and Kia vehicles, the TPMS may need to be reset after adjusting pressures by holding the TPMS reset button (usually located below the steering column) for several seconds until the light blinks. Your workshop manual includes the exact reset procedure for your model.
Oil Pressure and Temperature Warnings
These require immediate action on any vehicle. The oil pressure light means pull over and check the oil level now. On Hyundai and Kia vehicles with the Theta II engine family, low oil pressure should be taken especially seriously due to the known bearing issues in some production runs. The temperature warning means the engine is overheating – see our overheating diagnosis guide for the full procedure.
Diagnostic Resources
Hyundai and Kia use both standard OBD-II codes and manufacturer-specific codes. Browse our Hyundai workshop manual collection or search our catalogue at mechanicmate.net/shop.
