A TCU (Telematics Control Unit) can only be ordered with specification of the Vehicle Identification Number. When shipping the exchange TCU, the Vehicle Identification Number is encoded. Recoding is not possible. The TCU only functions properly with suitable encoding. Therefore, exchange TCUs cannot be ordered for stock! Retrofitting and conversions to SA633 are not possible! In case of impairment of the function of the Bluetooth functions, please first check the compatibility of the mobile phone software version with the TCU (see ASAP/parts and accessories/product information/search, keyword: compatibility matrix). ***** ***** ***** *****