Failure in Electrovalvula de la Caja

Good morning I hope someone can help me because I am already desperate because I already have many problems because of this, a couple of weeks ago I went to the workshop to make a change of time belt, oil and other maintenance details and on the way to the workshop of good to first and without prior notice I turned on the light of the box on the board of my renault symbol 2008 has 41000km Anyway, he took it to the workshop, they did all the maintenance requested by him to review that of the light of the box and the mechanic only told me that the scanner only said that it was a failure in one of the electrovalvulas of the box one that in particular according to it is very rare that there is damage therefore the review all the branches of the box even without finding the fault the fault Brushed and light the light again and then I don't know what it can be and I need the car I am on foot more than 2 weeks ago and even without finding the fault if there is someone who can recommend what to do I would appreciate it.