Your first read: understanding the result and what to do
Reading the vehicle step by step, the severity traffic light, clearing codes safely, seeing live data and asking for help.
Reviewed by Daniel Morales, founder of Reprorace SL, on
Where: Remote sessions › Diagnosis › Automatic diagnosis, and in the app, Vehicles › Diagnose
1. Before you start
- The unit plugged into the vehicle's OBD port, usually under the steering wheel.
- The ignition on; you do not need to start the engine.
- The unit active and connected. If it is not in the list, check it in “Tools”.
2. Read the vehicle
- Choose the unit and press “Diagnose”.
- Wait: the unit detects the vehicle, identifies it and reads every control unit. The screen shows what it is doing at each moment.
- If it does not recognize the vehicle, choose its type and press “Read anyway”.
3. Understand the result
| Traffic light | What it means |
|---|---|
| All good | No faults or important warnings in the control units that answered. |
| Some things to check | There are warnings or non-urgent faults: check them when you can. |
| There are serious faults | There is at least one serious problem, such as the warning light on: follow “What to do”. |
| The vehicle could not be read | No control unit answered: check the connection and the ignition and try again. |
Each problem shows its severity, the code, what it means and what to do, with the most serious first. In reads made with “Read vehicle”, the “In a nutshell” block shows the same traffic light above the full report.
4. What next
- Clear the codes: only after the repair and with the owner's permission. First you will see what is lost (warning light, freeze frames and inspection readiness) and you will have to confirm it with your second factor. If the fault is still there, it will come back.
- See live data: “See live data” takes you to “Watch live”; choose the dashboard and the duration. Use it to watch temperatures, engine speed or the battery with the engine running.
- Ask for help: “Ask a workshop or expert for help” takes you to the community's experts. In a personal account you can also ask your workshop for assistance.
- Report: “See the full report and sign it” opens every detail and the signed report for the customer.
| Message | What to do |
|---|---|
| The unit did not answer in time | Check that it is plugged in with the ignition on, and try again. |
| The unit is busy with another order | Wait for the other read or function to finish. |
| Confirm your identity with your second factor | It is required to clear codes: complete the verification and try again. |
| Your role does not allow reading vehicles | Ask whoever manages your organization for the diagnosis permission. |
Tip: If you do not know what to do with a red result, do not clear anything: ask for help and share the report.
More guides in this section
- How a remote session works
- Tunnel plan: connect a tool to the vehicle remotely
- Accept or withdraw remote access to your vehicle
- Collaborating in a session: messages, prompts and photos
- Unit PassThru mode from the app
- PassThru on Mac, Linux and iOS
- Assistance requests, appointments and work orders
- Legacy vehicle configuration and diagnostics: VAG and other makes
- Modern vehicle coding and programming
- Automatic diagnosis: one tap and it explains
- Reading a vehicle and sharing the report
- CANopen diagnostics for machinery
- Vehicle details: identifying it by the VIN
- Live dashboard, service functions and battery test
- v2 procedures: beta and operational
- Compatibility notices for your tool
- CAN captures
- Pre-purchase report
- Battery health of electric and hybrid cars
- Asking Diaglana for help
- Diagnosis options: each setting and when to change it
- Workshop settings: requests, orders, network and notices
- Reading: choosing the protocol and understanding the OBD on UDS report
- What a fault code means
- Live data: dashboards, recording and export
- Attaching fault codes to a work order
- Procedures that write, program or authenticate
- ISOBUS: reading and changing an implement's NAME
- Diagnosis over Ethernet (DoIP)
- Download Diaglana PassThru for Windows, Mac and Linux
- Authorizing a PC for PassThru
- Diaglana PassThru updates