The car does not respond to the read
Why a read does not find the vehicle and how to try again.
Reviewed by Daniel Morales, founder of Reprorace SL, on
| If you see… | What to do |
|---|---|
| The vehicle is not detected | Check that the unit is plugged in properly and the ignition is on. Choose the vehicle type and press “Read anyway”. |
| The vehicle does not answer: check the ignition is on | Turn the ignition on (without starting the engine if not needed) and start again. |
| The control unit asks for more time to answer | Wait: it is normal for some control units. The result arrives anyway. |
| The control unit is busy; the device stopped retrying | Repeat the read later or with the engine off. |
| Link failed | The unit could not open communication with that protocol. Try “Read vehicle” with another protocol or with automatic. |
| This unit's board (revision A) cannot perform some K-line starts… | It is not a fault of the vehicle: try another protocol or a revision B unit (guide “The unit's board revision”). |
| Failed (on a value) | The control unit said it had that value but did not provide it. The rest of the read is valid. |
| This function needs another tool | Your unit does not have that bus (for example J1850, J1708 or DoIP). The notice tells you which tool has it. |
On cars older than 2008 with a K-line, initialization takes a few seconds and some old addresses may not be available on your unit. Vehicles with another connector (9-pin truck, ISOBUS, boat) need an adapter cable.
Tip: No read message means that the car is broken: only that it did not answer that time. With a low battery, connect a charger before reading.