Diagnostics

Overview

The Diagnostics tab lets you read diagnostic values straight from a vehicle on demand. When the car is fitted with a TestHubLink device, TestHub can ask the vehicle for values such as battery state, range, or other supported readings and show them back to you in seconds — no cable, no separate tool.

Each value is shown as a tile with the most recent reading and the time it was taken. You can refresh any tile to fetch a fresh value from the car.

When the tab is available

The Diagnostics tab only appears on a car’s detail page when both of the following are true:

• The car is paired with a TestHubLink device.
• The Diagnostics feature is enabled for the car’s department.

If either condition is not met, the tab is hidden. The feature is off by default and is turned on per department by an administrator (see Administration for enabling department features).

What you can do

Action	Who can do it
View the tab and the last known values	Anyone who can open the car detail
Request a fresh read from the vehicle	Users with the uds.execute permission in the car’s department (or an elevated role)
Choose which values are shown as tiles	Users with the uds.execute permission (or an elevated role)

Without the uds.execute permission the panel is view-only: you still see the last known values, but the refresh buttons are hidden.

Reading a value

1. Open the car’s detail page and select the Diagnostics tab.
2. Find the tile for the value you want (for example, battery or range).
3. Click the refresh icon on that tile.
4. The request is sent to the vehicle through its TestHubLink. When the vehicle answers, the tile updates with the new value and unit, and the timestamp resets to “just now”.

Each tile also shows how long ago it was last read. Older readings are highlighted so you can tell at a glance when a value may be out of date.

The value catalog

Available readings come from a shared catalog of supported diagnostic messages maintained by the TestHub team. From the catalog you can pick which values appear as tiles for a given car:

1. Click the Tiles button in the top-right of the Diagnostics panel.
2. Tick the values you want to show and untick the ones you don’t need.
3. Save. The selected tiles appear for everyone viewing that car.

This lets each car show only the readings that matter for its testing programme.

When the device is offline

TestHub can only read from a vehicle while its TestHubLink is online and reporting. If the device has not reported recently:

• A banner explains that the device is offline.
• The last known values remain visible, so you always have the most recent reading on record.
• The refresh buttons are hidden until the device comes back online.

Notes

• Requesting a read queries the vehicle in real time, so a response may take a few moments depending on connectivity.
• Diagnostics reads do not change anything on the vehicle — they only retrieve information.