2TrakR

2021 Tahoe with 5.3 gas & about 60K miles. Short version: Parking Brake refuses to release after a brief stop (gas station, rest area). We are not manually engaging the parking brake, it is setting itself. No consistent means of resolution, other than waving a dead chicken above our head in a circle for an indeterminate amount of time. Long version: Drove vehicle more than 30 miles, stopped, shut off, did not manually set parking brake (never do). Came back to vehicle 5 minutes later, started, had red "PARK" lit on dash. Put vehicle in drive, vehicle would not move, acted like the parking brake was applied. Applying throttle did not move the vehicle, up to 1/2 throttle. Things attempted to resolve: Restarted vehicle. Shut off, got out with key fob, closed door, got back in, restarted. Attempted to put in brake service mode, steps would complete, but the yellow P with wrench would not illuminate nor the "brake service mode" message. Rationale was to forcibly disengage the parking brake by entering service mode. Shut off, opened/closed every door, got back in restarted. Brake service light illuminated, red "PARK" light was still on (flashing or steady, not sure). Vehicle was able to drive off. The above worked this one time. I presume all of the steps are just coincidental. Few weeks later, hopped in vehicle after had been sitting for a couple hours, fired up and noted "PARK" lit on dash, which went away within a second or so after putting it in drive, there was nothing noticeable about the parking brake being engaged and we never manually engage it. The "PARK" light is normally never displayed. A couple weeks later.... Vehicle driven for an hour, stopped and shut off for 5 minutes. Come back and "PARK" light illuminated and parking brake appears to be engaged as vehicle won't move. Tried all of the above (get out, open/close doors, etc). Had do steps for brake service mode, but would not activate (no P/wrench light). "PARK" still illuminated in red on dash. Investigated battery and had thoughts on what they could do to temporarily disconnect the battery. This mostly accomplished "more time" spent and nothing was actually done. One more attempt to start the vehicle and this time the brake service mode engaged, with the light and a message affirming it. Vehicle could then be driven. This is an 2021 and I'm pretty sure we have not replaced the battery. I've seen others indicate that the battery is a magic fix. I'm skeptical it's related to this since we are able to easily start the vehicle multiple times in a row and once started, it should have adequate power to disengage the actuators. We live in Michigan and do have plenty of salt driven through in the winter. Is there corrosion happening on the parking brake actuators? They are the original brakes. I've not had these apart; did have an 20 Silverado apart for a brake job and don't recall seeing anything exposed on the actuators to be concerned about, other than the caliper itself could be getting gunked up. Edit to clarify it is the "PARK" light that is lit; not Brake as I originally had. No codes. I do see low voltage on the scanner when the vehicle starts (10-12v) and it takes it several minutes to get up to the 14v range. Maybe it is a battery. I can manually engage the park brake and disengage. Parking on a hill, it will automatically engage the park brake. You can hear the actuators and the light on the dash matches what it should be doing. I can just put it in D and take off and it will disengage the park brake on it's own. That's when it's working as expected, not in the "won't disengage" instances. Other thoughts?

On the 16 Yukon SLT I drove, there were three settings for follow distance. The owner's manual talks a little about the settings. In my use, the system kicked in at a distance of about 5 seconds from the vehicle in front of you and then would slowly close that gap until it reached the "follow distance setting" that you chose. The nearest setting was close to 1 second behind the leading vehicle, the middle was 3 seconds. Not sure on the furthest, but seems like it was closer to the 5 second mark. That's based on speeds of 60 to 80. I didn't do a lot of time measurement at the closest setting, it was much too close for my comfort. The middle setting is where I did timing checks, but only by doing 1-one-thousand, 2-one-thousand. No actual stop watches were used ;-)

Tried it for 500 miles on a 16 Yukon and hated it. Guess I don't drive in the type of traffic that this works with. Slows down way before you are close enough to pass the vehicle in front of you. Will actively brake when the vehicle in the outside lane, in a curve, is going slower than you (65 to 45 in a second is not fun). Disables itself entirely if any small amount of snow on the front facia. Actively brakes to the set cruise speed after a passing event instead of just coasting back to the set speed. If you like to drive at the slow speed on the expressway, this will oblige. If you never want to pass anyone. If driving scares you. If you have no depth perception. If you don't have curves or hills. If you never tow anything. Works great for all of those scenarios. Simple fix for this is to have a button that disables the adaptive function and returns it to traditional cruise control. Then everyone is happy.