Your tech was close, but was using wrong count. You didn't say which code was showing.

TRY:

Key on:

Wait 3 second (use long count like 1 mississippi,
2 mississippi, 3 mississippi or stop watch.

Off pedal 7 seconds (Long count)

On pedal 10 seconds (Long count) hour meter should appear at 10 sec. mark then start fluxuating between code and meter, wait till excamation ( ! ) quits flashing then key off, then restart truck.
You can also try to disconnect battery negitive and wait 1 minute.
When you do the pedal dance make sure the floor board is back on truck.
If the code was for brake light switch, do the dance with the other foot pushing down brake pedal, not inching.