These little microcars are really economical, but you should really focus on small things such as the CVT and fuel systems. If your engine is having difficulty, the problem might be a dirty air filter or a broken temperature sensor. So, I came across a really good website, ManualMachine, where there is a
service manual for LIGIER X-TOO (it is in French though). The diagrams and schematics are quite clear and easy to understand. Generally, the battery is located under the passenger seat or deep in the compartment, so it definitely helps to see it in a diagram first rather than disassembling half of the interior blindly. Btw, did you try to disconnect the battery for several minutes to see if that would reset the problem on the screen?