If your check engine light appears right after installation...
Unit has been installed while the ECU was still active.
Improper connection. Plugs did not "click" or fully lock into place.
Turn off your vehicle, wait for the ECU to shut off, then uninstall the Pedal Commander unit. After, reinstall your vehicle's stock plugs and restart your vehicle. When check engine light clears, properly reinstall the Pedal Commander.
If your check engine light appears after a period of time...
Plugs were not locked in during the initial installation.
Modes were changed while cruise control was engaged or foot was on the gas pedal.
Uninstall the Pedal Commander and reinstall your factory plugs, allowing your ECU and CEL to fully reset. Once completed, reinstall the Pedal Commander following the proper installation.
If the lights on your Pedal Commander unit are not turning on...
Unit was not installed properly.
Check plug connection to make sure the plugs "clicked" and are locked in place.
Check engine lights can be cleared using an OBII scanner or by reconnecting your original plugs and then restarting your vehicle several times (5-6 times).