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Hanterill

The car does not appear.

Work down the list: what to check, in the order that finds the cause fastest, and what the transport does on its own when the link drops.

The car does not appear

Work down this list in order. The first two cover most cases.

  1. 01

    Is the car awake?

    A sleeping car answers nothing on the diagnostic bus. Turn the ignition on - you do not need to start it, and on an EV there is nothing to start.

  2. 02

    Is the RJ45 end in an Ethernet port?

    Not a USB-only port on a dock, and not a port that only carries power. The link light on the adapter is the quickest confirmation.

  3. 03

    Is a VPN or firewall blocking UDP 13400?

    Discovery is a UDP broadcast on port 13400. A VPN client that captures all traffic, or a host firewall set to block inbound UDP, will stop the car from ever announcing itself. Disable them briefly to test.

  4. 04

    Try another Ethernet adapter

    Some cheap USB adapters drop link-local traffic or refuse to come up without DHCP. A direct port on the laptop, or a known-good adapter, rules this out in one step.

  5. 05

    Is another tool holding the connection?

    One tool talks to the car at a time. Close any other diagnostic software, and give the gateway a few seconds after the last session ends before reconnecting.

One cable, one car

The cable goes from your computer to the car's diagnostic port, never to your home router, and never to a switch that also reaches your network. Do not bridge the car's network to your normal network.

When the link drops

Link recovery is built into the transport, so a brief interruption does not cost you the session.

Route re-activation
If the TCP connection drops, Hanterill re-activates the route on the surviving link and carries on with the same session.
Stale replies rejected
A reply that arrives on the old connection is discarded as stale, so a late answer cannot be mistaken for a fresh reading.
Keepalive
A TesterPresent every couple of seconds stops the car from putting modules to sleep in the middle of a long sweep.
Identity check
If the car reports a different identity after a reconnect, Hanterill ends the session rather than mixing two cars' readings into one file.