14.In the case of a programming error, the following screen is shown.
15.If this occurs, ensure the TrailerLink system ECU is powered and the connection from the Tool to the TrailerLink system harness is correct. Press the Check 
button to retry the operation; press the Return 
button to return to the learn procedure screen in step 5; or press the 
button to abort the learn procedure and return to the main menu.
16.If the Tool screen reverts back to the screen for entering the number of tires, then the number of tires entered does not match the number of tires currently programmed into the TrailerLink™ system receiver.
Make sure the number of tires entered on the Tool matches the number of tires being monitored by the TrailerLink system receiver and then return to Step 4 and repeat the Walk- Around Learn procedure.
Return
Selecting the Return icon moves the user to the previous menu screen.
Sensor Learn
To detect a sensor inside of a tire, press the Sensor Learn icon while holding the tip of the Tool’s antenna against the sidewall of the tire above the air valve.
Page 19