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Discussion Starter #1
Ok, so the EPB disengages when I put the car in L start driving the car.

Earlier in the evening, I put the car In Park and the EPB engaged automatically.

The manual states that this is possible but does not disclose the exact circumstances in which this happens.

Since its electronic why didn't they fully automate EPB engagement and disengagement?
 

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Exactly that ^

In towing instances, the car would have to be in neutral, however, there are circumstances when the parking brake isn't needed to be applied so to have it automatically engage every time isn't necessary.
 

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On that note about towing, it's too bad these don't come with tow mode similar to what some supercars have that set off an alarm if its being towed without a specific button being pressed.
 

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Discussion Starter #5
It happened again. I stepped on the brake then set the car to park and the EPB automatically engaged.

Can't get it to do that again.

Manual states:

The vehicle may automatically apply the EPB in some situations when the vehicle is not moving. This is
normal, and is done to periodically check the correct operation of the EPB system.
 

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It happened again. I stepped on the brake then set the car to park and the EPB automatically engaged.

Can't get it to do that again.

Manual states:

The vehicle may automatically apply the EPB in some situations when the vehicle is not moving. This is
normal, and is done to periodically check the correct operation of the EPB system.
Mine will auto engage every time in my driveway. I believe it's because my driveway is at a 30 degree angle.
 

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Mine will auto engage every time in my driveway. I believe it's because my driveway is at a 30 degree angle.
Yes. I have noticed when putting the Bolt into Park on a steep incline, the parking brake will automatically set. Also, when you remove the car out of Park in the same situation, the car will automatically disengage the parking brake.
 

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The manual also doesn’t state how EPB works and why/when one would need it:


  • Does EPB lock the rear wheel friction brakes, just like a “regular” vehicle would if one pulled up (or pedal-pushed) the manual parking brake lever ?
  • What if I don’t use the EPB in normal circumstances ? Just like when I put my other vehicle in “Park” I don’t usually bother with the additional parking brake. Does Park in the Bolt lock the transmission ? Or do you need EPB to keep it from rolling away regardless ?
 

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The parking brake is to lock the wheels from moving, mostly the rear wheels in common cars. It is a feature from the first cars that only had a manual transmission. This is a motion limiting action, and I see that it should never be fully automatic. You, as the driver, should be observing and acting this voluntarily, because someday you will need to move the car unpowered. And someday you need to immobilize it when you need to keep it still, so all parking actions need the driver to do it. Don't accept or trust a fully automatic electrical parking brake system (it is "electrical" not "electronic") because of the points I just mentioned.

The Bolt EV does some actions as a protective feature, but don't make it do all your job as the driver. And, yes, the Bolt EV's transaxle does have a "park pawl" that mechanically locks a gear and the axles from rotating.
 

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The Chevrolet Cruze (yes, Cruze) owners manual states: Under “Shifting Into Park" 1. Hold the brake pedal down and set the parking brake. 2. Hold the button on the shift lever and push the lever toward the front of the vehicle into P (Park)....

Conclusion: Parking brake-itis exists in GM owner manuals regardless of vehicle. Sure, from a product liability standpoint it’s better to advise the owner to always engage the parking brake - - who cares if he or another driver drives off later, when the parking brake wasn’t needed in the first place, and he doesn’t notice and burns up the brake pads & rotors.

Now to the Bolt given the same philosophy from GM. But, as per below references the application of parking brake is no longer a voluntary affair. So for those of us who are not addicted to the parking brake: we will now need to pay special attention to the red parking brake status light, in order to take whatever action might become necessary to turn it off.

FWIW, here’s the discombobulated list of references to “Electric Parking Brake” as found in the Bolt owner’s manual. (excludes safety and service warnings)

Under “Start Charge”:
The Electric Parking Brake will automatically apply once the charge process has been started.

Under “End Charge”:
The Electric Parking Brake should be manually disengaged before driving the vehicle.

Under Brake System Messages:
RELEASE PARKING BRAKE This message displays if the Electric Parking Brake is on while the vehicle is in motion. Release it before attempting to drive. [so the EPB was on, but only by a little bit?]

Under STOPPING THE VEHICLE/OFF:
Set the Parking Brake.

Under Shifting Into Park:
To shift into Park 1. Hold the brake pedal down and set the parking brake. 2. Press the button on top of the shift lever to shift into P (Park)….

Under Electric Drive Unit, One Pedal Driving:
If the vehicle cannot maintain the grade while using One-Pedal Driving, the Electric Parking Brake (EPB) may apply to hold the vehicle stationary. To drive again, press the accelerator pedal, and the EPB will automatically disengage.

Under Electric Parking Brake, EPB Apply:
To apply the EPB: 1. Be sure the vehicle is at a complete stop. 2. Pull the EPB switch momentarily. The red parking brake status light will flash and then stay on once the EPB is fully applied.

Under Electric Parking Brake, EPB Release:
To release the EPB: 1. Press POWERO to start the vehicle. 2. Apply and hold the brake pedal. 3. Press momentarily on the EPB switch. The EPB is released when the red parking brake status light is off.

Under Electric Parking Brake, Automatic EPB Release:
The EPB will automatically release if the vehicle is running, placed into gear, and an attempt is made to drive away. Avoid rapid acceleration when the EPB is applied, to preserve parking brake lining life.
 

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Not sure of the source (likely one of the numerous YouTube videos now proliferating on the Bolt) but I recall hearing the Bolt is equipped with an incline sensor. When the car senses it's on a slope when parked, it automatically sets the EPB. The guy didn't say how many degrees of slope is required before the EPB is set.

Another useful safety automation I learned about is that the Bolt will also automatically shift itself into Park when the driver's door is opened. The Chevy designer being interviewed noted this is a uniquely important feature for Bolt drivers. With the Bolt, simply driving in Low will completely stop the car, making it easy to forget the car is actually still in gear when it's not moving and the driver's foot is not on the brake.
 

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That definitely is convenient. Can't see how people would be forgetting it in park though as it requires you to literally push a button but nonetheless, I'm sure it happens. The Bolt does activate the EPB on incline though, how much, I'm unsure of, but I would presume when it's sufficient enough that rolling is a possibility upon failure.
 

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The Bolt does activate the EPB on incline though, how much, I'm unsure of, but I would presume when it's sufficient enough that rolling is a possibility upon failure.
No, the Bolt does not always engage the EPB to prevent rolling. Sometimes the brake activates, sometimes it does not and you can roll slowly forward in L.

I don't know why GM was unable (or unwilling) to perfect this useful feature.
 

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The Bolt does activate the EPB on incline though, how much, I'm unsure of, but I would presume when it's sufficient enough that rolling is a possibility upon failure.
No, the Bolt does not always engage the EPB to prevent rolling. Sometimes the brake activates, sometimes it does not and you can roll slowly forward in L.

I don't know why GM was unable (or unwilling) to perfect this useful feature.
If your in L and and incline then I have no idea.
If you put the car in park on an incline (certain slope, not sure how much) then yes it ALWAYS applies the parking break(EPB). My driveway is 20-25 degree angle and the parking brake has always but auto applied. I have parked in my driveway about 25 times.
 

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The Bolt does activate the EPB on incline though, how much, I'm unsure of, but I would presume when it's sufficient enough that rolling is a possibility upon failure.
No, the Bolt does not always engage the EPB to prevent rolling. Sometimes the brake activates, sometimes it does not and you can roll slowly forward in L.

I don't know why GM was unable (or unwilling) to perfect this useful feature.
In L I don't know.
In park on a slope it ALWAYS applies parking brake(EPB). Driveway is 20-25 degrees and parked about 25 times. Parking break applied 100% of the time.
 

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The parking brake is to lock the wheels from moving, mostly the rear wheels in common cars. It is a feature from the first cars that only had a manual transmission. This is a motion limiting action, and I see that it should never be fully automatic. You, as the driver, should be observing and acting this voluntarily, because someday you will need to move the car unpowered. And someday you need to immobilize it when you need to keep it still, so all parking actions need the driver to do it. Don't accept or trust a fully automatic electrical parking brake system (it is "electrical" not "electronic") because of the points I just mentioned.

The Bolt EV does some actions as a protective feature, but don't make it do all your job as the driver. And, yes, the Bolt EV's transaxle does have a "park pawl" that mechanically locks a gear and the axles from rotating.
Thank you. As a pilot, I can tell you, don't 100% depend on automation to save you. Always take personal responsibility for driving the car and securing the car.

I have wondered though, about this in this new age of EPBs. In my day the parking brake was also called the "E-Brake", or emergency brake. Something to slow, or stop the car incase the hydraulic brakes were to fail. The E-Brake did save me personally once when the brakes went entirely on my '62 Dodge Lancer. Prevented me from crashing through a fence. With this new EPB, what exactly happens when you flip that switch and the car is in motion?
 

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With this new EPB, what exactly happens when you flip that switch and the car is in motion?
Guessing: based on a few clues from the owner's manual:

It won’t be the same result as you achieved as a teenager when for no reason other than experimentation, you pulled up hard on the parking brake handle/emergency brake and smoked the rear tires (or not..).

Assuming there’s no problem with the hydraulic braking system. Perhaps the Bolt will come to a stop quite quickly on its own while displaying the message RELEASE PARKING BRAKE. During this maneuver the Bolt will sense “ignition-on” and vehicle in-gear. And given this condition will apply only moderate friction brake pressure via the EPB. Don’t know if the brake lights would go on.

As opposed to full friction pressure via EPB if vehicle in Park, or perhaps if vehicle facing upward on a slope greater than X degrees. (can Bolt sense a hydraulic system failure and then allow full pressure via EPB?)

I doubt whether the electronic brake control module (stability control) would come into play when enacting EPB on a roll. As I’m assuming the Bolt’s EPB is just an alternative to the cable in older vehicles, serving only as a backup or supplemental mechanism, as conditions warrant, to the hydraulic system for friction braking.

Now watch: someone who possesses a Bolt and has tried applying EPB with vehicle in motion, will prove the above wrong.:rolleyes:
 
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