C1503TCS/ESC OFF switch fault

• Hyundai/Kia code · ABS / stability control
• Lights a warning lamp

How the car detects it

The button that switches traction/stability control off reports an impossible state.

What you may notice

• ESC warning light

Likely causes

• PossibleSwitch or its wiring
• RareABS/ESC unit internal fault

Sources

• static.nhtsa.gov › RCRIT-22V800-5083.pdf · official document

Backed by an official manufacturer document.

From Obdaryn's Hyundai/Kia pack, exactly as the app shows it, with the public sources above. Guidance only; confirm with a workshop.