This check means that you will have to take the fairing off - not an easy job to do on your own without the risk of marking/scraping some of the paintwork or the front fork anodising.
Check the mating of the small, brown 7 pin connector in the connector-group-aperture plate on the upper LHS of the wiring behind the instrument panel.
The temp, tacho, fuel and boost gauges all get their signal through that connector.
Take the connector apart, clean its two parts (male and female), give it some dielectric grease, and re-connect it - should cure your problem.
If it wasn't pushed together properly, just put some of the grease on and push the two parts SOLIDLY together.