| 1 | Arabic, English (Instruction manual) Asia | B5A-3140-20.PDF | Download | 1,301 kB |
| 5 | Dutch, English, French, German KDC-BT440U, KDC-BT640U | B5A-3141-10b.PDF | Download | 3,144 kB |
| 6 | Dutch, English, French, German, Italian, Portuguese, Russian, Spanish, Ukrainian (Quick Start Guide) Europe | B5K-0650-30.PDF | Download | 2,457 kB |
| 1 | KDC-BT640U_EU_Doc_2024-06-21_KENWOOD.pdf | Download | 391.4 kb |
| 2 | KDC-BT640U_EU_DoC_2025-07-31_KENWOOD.pdf | Download | 410.45 kb |
| 3 | REDoC_Cover Letter_KDC-BT460U_KDC-T822BT.pdf | Download | 128.95 kb |
| 1 | Amazon Alexa | /car/app/amazon_alexa/eng/index.html?model=KDC-BT640U | |
| 2 | KENWOOD Remote | /car/app/kenwood_remote/eng/index.html | |
| 3 | 2020 CD/USB receiver firmware updates | (12 November 2020) | /cs/ce/receiver/firmware/2020/2020b/eng.html |