Experimental: Bluetooth tachograph download (beta)

The free TachoAssist Card Reader app for Android can now download data directly from a version 2 smart tachograph over Bluetooth. You can download data from the driver card inserted in the tachograph, or from the vehicle unit’s memory with a company card inserted. No card reader or cable is needed. You get the same signed .DDD file as you would with a download key or USB card reader. The file stays on your phone unless you send it to your TachoAssist workspace.

This feature is new and does not yet work with every tachograph. It does not support older version 1 tachographs or models without Bluetooth. You need to be next to the vehicle to download the data. You can still read driver cards with a USB reader as before.

• A version 2 smart tachograph with Bluetooth. Look for “GEN2 v2” on its printouts and a Bluetooth symbol on the front panel.
• Your own driver card in slot 1 to download your card data.
• A company card inserted in the tachograph to download vehicle unit data.
• An Android phone with Android 8.0 or newer and Bluetooth Low Energy.

Bluetooth download support depends on the tachograph’s software version. The table below shows what we expect based on manufacturers’ documentation and drivers’ reports so far. We will update the last column as drivers confirm which configurations work.

First field confirmation: VDO DTCO 4.1x, driver card, beta4, 14 Oct 2026.

If your version is listed as “Not expected to work”, you can still try it. A report of what happened is just as useful to us. VDO DTCO 4.1 and Stoneridge units with SWID 1214 or 1619 also require a mandatory security update, which a workshop must install by the next periodic inspection. The updated versions are listed in the “Expected to work” rows.

Where to find the software version:

• VDO: on the tachograph, display → vehicle → DTCO version; or the “Technical data” printout (“V 4141” and so on).
• Stoneridge: OK → INFO → Product and certification (the SWID); or the “Technical data” printout.

Older units, including VDO DTCO 4.0 and 4.0e, Stoneridge SE5000-8 (Smart 1) and other manufacturers’ version 1 tachographs, have no Bluetooth download interface. Bluetooth adapters that plug into the front socket, such as VDO SmartLink or Stoneridge Tacho Link, use their manufacturers’ own connection systems and do not work with this app.

1. Download the .apk file on your phone and open it.
2. Chrome may warn that this type of file can be harmful. Choose Download anyway.
3. If Android asks for permission to install apps from this source (Chrome or Files), allow it.
4. If Google Play Protect says it does not recognise the app, choose More details and then Install anyway. Play Protect shows this for apps that are not installed from Google Play.
5. Install the app.

The beta updates your existing TachoAssist Card Reader installation if you have version 1.0.6 or newer, keeping your settings and saved files. If you have the September 2026 test build (version 1.0.5), uninstall it first. Android cannot update that build and will show “App not installed”. Before uninstalling, upload or save a copy of any files still waiting in the app. The app will notify you when the next regular release is available. You can install that release over the beta.

Chrome and Play Protect messages vary between versions. Look for the button names in the steps above; their position and highlighting may differ.

1. Park the vehicle and switch the ignition on. Stay within 1–2 metres of the tachograph for the whole download.
2. Disconnect any download key or cable from the tachograph’s front download socket. The tachograph disables Bluetooth downloading while anything is connected to that socket.
3. Insert only the cards you need: your driver card in slot 1 to download card data, or a company card to download vehicle unit data. After inserting a card, wait until the tachograph’s menu is available. Pairing will fail while the tachograph is still reading the card.
4. Note the tachograph’s software version (see the table above). This is the first detail we will ask for if you need help.
5. On the phone, switch Bluetooth on. VDO only: the phone’s Bluetooth name must be 14 characters or fewer, or the DTCO refuses the connection. You can change it under Settings → About phone (or Settings → Bluetooth) → Device name.

The first time you download over Bluetooth, you will see the following prompts in order: our short notice about the feature and diagnostic reports (see below); Android’s request for access to Nearby devices; a request to turn on Bluetooth if it is off; and Android’s pairing request with a 6-digit code. On Android 8–11, the permission request is for Location instead of Nearby devices. Location must also be switched on, as these Android versions require it to find Bluetooth devices.

On the app’s main screen, tap Download from a tachograph over Bluetooth (beta). The app shows the same steps:

1. Insert the card in slot 1 and wait until the tachograph’s menu is available.
2. Data sharing for ITS must be enabled for the card: entry driver 1 → settings → publish ITS data → yes. You were asked “publish ITS data?” the first time you inserted the card into this tachograph. If you answered no, you need to change that setting here before you can use Bluetooth with the card.
3. Start pairing: OK, ▼▼ to “entry driver 1”, OK, ▼▼▼ to “✱ Bluetooth”, OK, then OK on “pairing”. The tachograph shows “please connect”.
4. Select “DTCO-…” from the list on your phone.
5. Compare the 6-digit code on both screens. Confirm on the phone, then choose “yes” on the tachograph and press OK. The tachograph shows “entry stored”, and “✱” appears in the top row of its display.
6. To download vehicle unit data, insert the company card in slot 1 and pair through the “entry driver 1” menu.
7. Connection problems: reset the Bluetooth controller — display → vehicle → DTCO version, hold OK for 8 seconds (DTCO 4.1b).

Pairing is linked to the card inserted in the tachograph at the time. If you change cards, for example from your driver card to a company card, remove “DTCO-…” from your phone’s Bluetooth settings and pair again with the new card inserted. With a company card inserted, you can remove an old pairing through entry vehicle → ✱ Bluetooth manage devices. Removing the driver card switches off the tachograph’s Bluetooth; reinserting it switches Bluetooth back on.

On the app’s main screen, tap Download from a tachograph over Bluetooth (beta). The app shows the same steps:

1. Insert the card and make sure the export of personal data is allowed: SETTINGS → Drivers Consent → YES. The first time you inserted the card into this tachograph, you were asked “OK to exp pers. data?”.
2. Turn on Bluetooth on the tachograph: OK → SETTINGS → Bluetooth → Enable Bluetooth → YES.
3. Start pairing: SETTINGS → Bluetooth → Pair new Device? → OK. The tachograph remains available for pairing for 5 minutes.
4. Select “SE5000-…” from the list on your phone.
5. When the code appears, choose YES on the tachograph and confirm on the phone. The tachograph shows “Pairing Complete”, and the Bluetooth symbol appears next to driver 1’s activity.

The tachograph remembers your phone separately for each card. Next time, connect through SETTINGS → Bluetooth → Paired devices → your phone → Connect to. To start again, remove your phone from Paired devices on the tachograph and remove “SE5000-…” from your phone’s Bluetooth settings.

After pairing, the app asks What do you want to download?

• Driver card – slot 1 (or slot 2 if two drivers’ cards are inserted). You can download your own card with just a driver card inserted. The tachograph records the download date on the card, just as it does when you use a download key, so the 28-day reminder resets.
• Vehicle unit data requires a company card in the tachograph. Choose which data to download: activities for a period of 1–365 days (28 days by default); events and faults; technical data; and detailed speed data. The overview is always included. Detailed speed data takes much longer to download because of its size. If a company lock is active, the tachograph provides data only for the periods your company is entitled to access.

Keep the screen on and stay close to the tachograph. Downloading a driver card usually takes one or two minutes; vehicle unit data can take several minutes.

The app never saves an incomplete download. If the connection drops or the data does not arrive in full, nothing is saved and the app displays a message. Try again. If the tachograph does not provide an optional section, such as detailed speed data, the app saves the available data and shows a note, for example “Detailed speed: not available on this tachograph.”

If you are signed in to TachoAssist, the file is sent to your workspace, just as it is after a USB card read. Otherwise, it is saved on your phone. Vehicle unit analysis is available with TachoAssist business plans. If you use a driver account, the file stays on your phone and the app explains why.

The app explains the problem in plain language, for example “The tachograph refused the download. Pair again while the card you want to download is in the tachograph, and check that the card releases ITS data.” Then try the following steps in order:

VDO DTCO 4.1x

1. Try again.
2. Switch the ignition off and on.
3. Reset the Bluetooth controller: display → vehicle → DTCO version, hold OK for at least 8 seconds (DTCO 4.1b).
4. Remove the pairing from both devices and pair again through the menu for the slot containing the card you are using.

Stoneridge SE5000-8.1

1. Try again.
2. Switch the ignition off and on.
3. Remove your phone from Paired devices on the tachograph, and remove the tachograph from Android’s Bluetooth settings. Then pair again.

Do not cut the vehicle’s main power to “reset” the tachograph. An interruption of the power supply is recorded as an event in the tachograph and can be seen at a roadside check. If you ever do it as a last resort, note the time and keep a printout.

The first time you open Bluetooth downloading, the app explains the feature and asks whether you want to send diagnostic reports. There are two equally prominent buttons: Send reports and continue and Continue without sending. Downloading works the same whichever you choose.

Diagnostic reports help us make downloading work with more tachographs. A report contains:

• the app version, the phone model and the Android version;
• the tachograph model and software version, if the tachograph provides them;
• the connection steps and any error codes;
• a random report code and a random ID created on your phone, which lets us group reports from the same phone;
• a tag that lets us identify reports from this phone about the same tachograph. It is calculated on your phone using the tachograph’s Bluetooth address and a random key that never leaves the phone.

A report never contains the driver’s name, card number, vehicle registration, VIN, location, or any data from the card or the tachograph file. It is not linked to your TachoAssist account, even when you are signed in, and it is deleted after 90 days.

• Settings → Send diagnostic reports automatically shows your current choice and lets you change it at any time.
• Settings → Diagnostic reports shows reports that have been sent or are waiting to be sent, along with their codes. If you choose Reset report ID, new reports will no longer be linked to earlier ones.
• If a download fails, is interrupted or produces a file that TachoAssist rejects, you can use Send a report… regardless of your automatic reporting setting. You will see everything that will be sent and can add a comment. Please do not include names, card numbers or vehicle registrations. The report is sent only when you tap Send.
• Attaching the downloaded file requires separate confirmation. The app explains that the file contains personal data and asks whether you want to include it. We use the attached file only to investigate the problem and delete it within 30 days.

When a report is sent, the app shows its code, for example TA-7K2M-Q9WD. Full details are in the privacy policy.

Whether it worked or not, we want to know. Post in the Reddit thread where you found this page, or write to contact@tachoassist.com:

• the report code, if the app sent a report;
• the tachograph make, model and software version (from the display or the “Technical data” printout);
• which cards were in each slot and whether you downloaded driver card or vehicle unit data;
• what the tachograph display said, word for word, if something went wrong.

Never post a .DDD file, printout, photo of a card or vehicle registration number publicly. The report code is enough for us to find your report. If we need the file, we will ask for it by email.

Use the app only while the vehicle is parked. Download only data you are entitled to download: your own driver card, or your company’s vehicle data with your company card.

This experimental feature is available as a free beta, with no guarantee that it will work with a particular tachograph. A complete file saved by the app is the same file the tachograph would provide to a download key. Check that your files have been received before relying on the download to meet your deadlines.

Bluetooth® is a registered trademark of Bluetooth SIG, Inc. VDO and DTCO are trademarks of Continental Automotive Technologies GmbH; Stoneridge and SE5000 are trademarks of Stoneridge, Inc. TachoAssist is not affiliated with or endorsed by these companies. We use their names only to identify the tachographs the app works with.