PSI-Design.co.uk

Td5 Diagnostics

Td5 Diagnostics turns a small, low-cost K-Line dongle into an ELM327-style OBD2 scanner for
Land Rover Td5 engines, with a free app to read it. It shows live engine data and reads and clears
fault codes – including the parameters unique to the Td5 – so you get much of what an
expensive tool like Nanocom offers, for a fraction of the price.

What you need

  • The Td5 diagnostic dongle (an ESP32-S3 plus a K-Line interface). Build files
    and a ready-to-order PCB are on GitHub, or ask me for a made-up one.
  • An Android phone or tablet for the app, or any device with Chrome/Edge for the
    web version.

Install the app

Android app:

  1. On your phone, download
    Download Android App (APK)
  2. Open it from your Downloads. Android will warn it is from an “unknown source” –
    that is normal for any app installed outside the Play Store. Allow it, then tap Install.
  3. A Play Store version is coming; once it’s live it will be linked here.

Cross-Platform Version: The app also runs in any Chromium browser (Chrome or Edge, on Android or a PC); on an iPhone or iPad use the free Bluefy browser:

Open Web Version

On an iPhone or iPad, you will need to use the free Bluefy browser as the standard one does not support Bluetooth.

Using it

  1. Plug the dongle into the vehicle’s diagnostic socket (OBD pin 7) or ECU pin B18,
    and switch the ignition on.
  2. Open the app, tap Connect, and choose “OBDII” from the list.
  3. There are four tabs – swipe left/right to move between them:
    • Fault Codes – read and clear DTCs (with Td5 descriptions), and see the
      vehicle’s VIN and current fuel-map name.
    • Available Data – choose which values to display or graph, pick your units,
      and tick a box to log everything to a CSV file.
    • Live Data – your chosen values, updating live.
    • Graphs – up to four auto-scaling charts.

Downloads & source