A funny thing happened on our last trip The multi-function panel warning came on (beep beep) informing me that we were nearing our range limit. It's a Fiat Ducato 160 multijet. Autotrail tracker EKS se. The said multi- function showed a fuel range of 350 miles. The fuel gauge showed about half full. The warning is intermittent, sometimes 5mins sometimes 30mins. Filled up and as soon as we moved it beeped again. Weird. Anyone any ideas??