Relearn most likely won't solve that, especially when you see the procedure:
(7) The 5.7L V-8 engine is equipped with a fully electronic accelerator pedal position sensor. If equipped with a 5.7L, also perform the following 3 steps:
(a) Connect negative battery cable to battery.
(b) Turn ignition switch ON, but do not crank engine.
(c) Leave ignition switch ON for a minimum of 10 seconds. This will allow PCM to learn electrical parameters.
(d) The DRB IIIt Scan Tool may also be used to learn electrical parameters. Go to the Miscellaneous menu, and then select ETC Learn.