Why not call the dealer and ask them where they are? I would think if it's to do with "brake assist", they're on the nose somewhere, perhaps the bumper?
2018 (2017 Sprinter Cab Chassis) Navion24V + 2016 Wrangler JKU (sold @ ????) - 2016 Sunstar 26HE (sold @ 4600 miles) - 2002 Roadtrek C190P (sold @ 315,000kms)