NHTSA Complaint #11421099 — 2017 CHRYSLER PACIFICA

This is my 3rd problem to be reported to NHTSA on this 2017 Chrysler Pacifica. The "L" gear should typically slow down the vehicle when engaged, especially going downhill, so that you can use the transmission to slow the car down and use less braking. On a recent trip on I-5 the Grapevine, i used the L gear to attempt to slow down the vehicle on a steep and long descent. Instead of slowing the vehicle down immediately upon switching to L, the vehicle actually sped up 10 to 15 mph initially before it starts to slow down the car, creating a very dangerous situation especially when vehicles in front of me were slowing down too on the descent. I took it to the dealer, and they actually replaced the TCM because of another dangerous problem (see Complaint 11405469, March 2021) with the vehicle. I have tried the "L" gear again after, and it still does the same thing. The dealer says they cannot replicate the problem because there is no downhill where they can test for this problem.