Our Preloaded Tune Files are made using your vehicle's factory calibration. You should not lose cruise control after tuning with our device. Connect your device to your vehicle then return the vehicle to stock.
If after returning the vehicle to stock, your cruise control still doesn't work or function properly, you may want to give us a call with the device, the vehicle, and access to a Windows PC with internet access to further troubleshoot with one of our Customer Success Agents.
Note: On the 2011+ Duramax 6.6 models, cruise control will be disabled if you remove the speed limiter. To get cruise control back you will have to enable the speed limiter.