The yellow light on the right side of your instrument cluster, and right below the tachometer, would be the check engine light. This means (at minimum) that one of the sensors of the engine is communicating a problem or malfunctioning.
RepairPal Certified shops can diagnose and repair your 2003 Volkswagen EuroVan. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.