[BR3W CITY]

Tac module itself could be failed/grounded out. When its already at operating temp, does it idle normally (if your not driving, just sitting there)?

If there is a large enough misfire, or you rapidly decelerate, the load change to the engine can bog it out, trigger a "low engine power" code, and limp the truck. On a dbw setup that means killing the pedal input. Can it maintain an idle on its own?

When you mentioned the temp, I thought it possible that when the truck came off of cold-start, the idle was dropping too low to maintain, triggering either a miss or low power fault and killing the pedal.

For ****s, I disconnected the tac and pedal from each other, pulled the battery for 20 minutes. Re-connected them while it was off, put the battery back on, started the truck and let it do a full idle-warmup. The fault never came back after that.