This means "Acknowledgement Failed"
Things to try/Check for:
If you continue to run into this error, please contact our Technical Support Team using the "Contact Support" button below. Please make sure to have your device, vehicle, and access to a PC computer.
6.4L Ford SuperDuty
The Glow Plug fuse is number 27 on the fuse box located in the engine compartment, try pulling it and loading the tune or returning to stock again with fuse out.
Turn key to the on position before hooking up the device and ignore all key prompts through the tuning process.
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