Correct answer: As long as the circumstances that caused it last.

Detention due to an emergency lasts as long as its cause persists, for example until a breakdown like the one affecting the passenger car in the image is resolved. The limit of less than 2 minutes without leaving the vehicle applies to Stopping. Even so, if your vehicle is obstructing the roadway, you should try to move it out of the way as soon as possible.

Real Decreto Legislativo 6/2015, de 30 de octubre, por el que se aprueba el texto refundido de la Ley sobre Tráfico, Circulación de Vehículos a Motor y Seguridad Vial · Real Decreto 1428/2003, de 21 de noviembre, por el que se aprueba el Reglamento General de Circulación