appreciate the input Raymond but the owners manual really doesn't address my issues (page 200 included)
this vehicle does not have any forward sensing systems (adaptive cruise, pedestrian braking or even lane departure, those are all extra's on the XT4 which means extra cost)
here's the main issue.. wife backs out of the garage and into a turn around area (about a 100 feet) she then puts the vehicle in drive and starts to roll down the driveway which is about a 10 degree slope (relatively steep) because of this she has neither her foot on the brake (yet, but will soon as the vehicle accelerates) nor her foot on the gas.. at this point the vehicle is going at a brisk walk or close to a jogging speed.. the vehicle has just done an up shift, and then immediately after that a downshift, and then it lurches a couple times and brakes itself to a complete stop..
all this has been video'd and demonstrated to the service manager of the dealership where the vehicle was purchased.. GM's response is "it shouldn't do that".. this failure mode does not occur every time but probably about 1 in 5.. in the video GM technical can see everything that's displayed on the dash..
when the vehicle is in this situation (lets call it failure mode) this is what we've tried.. setting park brake with park brake switch and then releasing bark brake by pushing brake peddle.. (as the manual says) .. if you give the vehicle any gas it will creep forward but has resistance as though your holding the brake pedal.. the moment you take your foot off the gas the car returns to a complete stop.. now keep in mind the driveway in this location is steep enough that the car should be rolling like crazy.. we've also tried pressing the brake peddle firmly a number of times with no result.. the only way the vehicle can be made to "resume normal operation" is to either shift it into either neutral or park and then back into drive and then off you go..
okay so now the good stuff.. the shop foreman is in the car, scanner plugged in and he's ready for anything.. car goes into failure mode and he see's nothing on the scanner.. he searches through all the BCM's and nothing.. so now I put the vehicle into park and the dash displays the park brake symbol as well as the DIC saying "park brake set".. the only problem is the scanner says it isn't.. it says that the park brake switch is "applied" but non of the park brake components are active.. we tried this a number of times with the same results.. if you applied the park brake yourself by utilizing the park brake switch the system worked as advertised, but if you got the "park brake applied" indication when in the hill assist situation it was in fact not..
So now GM Technical has the video's, scanner snap shots from the dealers service people and the questions about why does the park brake say it's set, when in fact it's not (according to the dealers expensive scanner).. and here is what GM has come up with to date..
they want the dealer to check for contamination of the transmission fluid..
they noticed in the video the drivers seatbelt warning lamp illuminated.. this is because about 300 feet down the driveway you need to get out and open a gate.. neither my wife or I can honestly say whether or not this failure mode has happened when wearing the seatbelt.. GM says the car is breaking to a stop possibly because the driver isn't wearing their seatbelt.. really?
now Raymond you refer to the newer vehicles being intelligent? I find it unusual that the vehicle would be so intelligent that the people that built it don't even know what it's doing.. makes me think that I'm not driving a vehicle but a HAL 9000..