Transmission does not downshift properly from upper gears (5,6) to lower range when decelerating from 40 + mph to under 20 mph. vehicle will exhibit loss of power from being in too high of a gear range, causing "chugging", and then a sudden burst of power as you try to accelerate. dealer reset ecm for transmission; problem persists. typically occurs on residential or non-freeway streets, but has happened entering a freeway entrance ramp.
Vehicle stalls. when navigating a corner transmission looses its gear and acts like it doesn't know what to do and bangs and stalls. also trans acts confused stop and go situations(city) and bangs when it remembers. also does this when coasting on highway and accelerating again. it may jump down several gears and take off. vehicle also has stalled several times at red lights and has a rough idle most of the time like it wants to stall. been in shop numerous times for same thing and advised chevy but they cant figure it out and it is still doing it. also looked online for possible answers and there are a lot of these same problems reported with no answers.
The transmission hesitates while trying to find the correct gear..i spoke to a maintenance rep at the dealership where i bought my truck and he said that the engineers made the truck that way for fuel efficiency. he also told me to just floor the accelerator to get power when i need it. it still hesitates even when i floor it and how does that help fuel efficiency? he said if a technical service bulletin comes out on this issue that i can bring in my truck and they will fix the issue. i am scared to pass a vehicle unless absolutely nothing is coming for fear of the time it takes for the truck to find the correct gear. it also kind of jerks when it does find the right gear. this has been going on since i purchased it in january of 2016.
Chevy said there are no fixes for the following complaints. transmission is acceptable and smooth shifting under light loads. under a need for downshifting for acceleration the down shifting is delayed or hesitates momentarily and then the truck jerks forward to a excessively lower gear & the upshifts to the gear it should have in the first place. the delay or lag in downshifting creates a very dangerous condition when needing instant power. there is much difficulty when merging into traffic when power is needed.. manipulating the manual shift can cover up this defect on some occasions when if you have time to plan for it. the transmission also shutters at low load many times resulting in no power until you downshift. then this downshift is delayed and then becomes abrupt again. the shutter feels like the truck is going over small bumps in the road. the transmission shifting is certainly not correct and certainly results in unsafe situations. i should have test driven the truck under more conditions than i did and probably would not have purchased it. i hear that this problem can be fixed with an aftermarket computer update. chevy probably dose not want to admit that in order to have the gas mileage ratings the transmission must bet this way. also note that the 2017 colorado will have an 8 speed transmission.