Sorry, I have no idea - I brought it to the shop to fix it (both times).
Mine was on and off, with no noticable pattern.
If yours is doing it only when slowing, then my guess is that the wiring is grounding out in only one direction when the chassis flexes on deceleration.
Wiring is not like an alternator or other fixed part - the wiring runs are by nature a little different on every car, so these kinds of issues are going to be unique to yours. When you slow down, you are throwing weight forward in the vehicle. Your wiring harness may only be grounding out where it hits the frame or something as it shifts forward under deceleration.
I paid for 3-4 hours of labor on each of my two ToD wiring repairs - it takes a while for the mechanic to diagnose, find, and fix this kind of problem.
G