How's your system voltage? Does it drop below 12.5 or so when your van is at a standstill? I'm thinking a microcontroller is sensitive to low voltage. Could indicate an alternator / voltage regulator issue, or even a questionable battery.
The fan microprocessor controller is between the fans on the center radiator mount. Powering that, IIRC, is a cube relay in the fuse box next to the battery. Check inputs and outputs of these components to track down your issue.
The fan microprocessor controller is between the fans on the center radiator mount. Powering that, IIRC, is a cube relay in the fuse box next to the battery. Check inputs and outputs of these components to track down your issue.