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I'm guessing a percentage indicator is using a calculation based on miles driven. I know that sensors work by wearing down with the pad until a wire is exposed setting off a dash light. But a percentage indicator seems like it's a guestimate. Otherwise, it would need to be continually measuring pad thickness.
 

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I'm guessing a percentage indicator is using a calculation based on miles driven. I know that sensors work by wearing down with the pad until a wire is exposed setting off a dash light. But a percentage indicator seems like it's a guestimate. Otherwise, it would need to be continually measuring pad thickness.
One thing that bothers me with readouts is the lack of readouts. You need to connect a scanner to your car to read out a code. With everything going software based as the main user experience (ie info entertainment ) the car should simply tell you what's wrong but I guess car companies want to keep repair shops open.
 

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One thing that bothers me with readouts is the lack of readouts. You need to connect a scanner to your car to read out a code. With everything going software based as the main user experience (ie info entertainment ) the car should simply tell you what's wrong but I guess car companies want to keep repair shops open.
Honestly, I think it would end up just being more trouble than a help. People that know what to do with code information often (bordering on always) already have OBD readers or intend to get them before they even have both metric and SAE wrenches. People that don't know what to do with the information behind the codes are going to need help and advice anyway, whether they get it from a forum, a manual or a dealership service department anyway.
 

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2019 Chevy Volt LT with 7.2 kW Charger
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I'm guessing a percentage indicator is using a calculation based on miles driven. I know that sensors work by wearing down with the pad until a wire is exposed setting off a dash light. But a percentage indicator seems like it's a guestimate. Otherwise, it would need to be continually measuring pad thickness.
I don't think it's going to just be miles driven, the car knows the speed, regen, and when the physical brakes are used too... so it's a little more accurate than that.
 

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I don't think it's going to just be miles driven, the car knows the speed, regen, and when the physical brakes are used too... so it's a little more accurate than that.
You'd hope, but so far I'm not finding any details. I also looked in the 2022 Hummer EV Owners Manual.
 

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I'm guessing a percentage indicator is using a calculation based on miles driven. I know that sensors work by wearing down with the pad until a wire is exposed setting off a dash light. But a percentage indicator seems like it's a guestimate. Otherwise, it would need to be continually measuring pad thickness.
Measuring piston travel or fluid displacement in the brake line doesn't seem THAT tricky. Just finicky due to small amounts/measurements between 95% and 5%.
 

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Measuring piston travel or fluid displacement in the brake line doesn't seem THAT tricky. Just finicky due to small amounts/measurements between 95% and 5%.
Why not lasers? :cool:

I'm thinking this may be a future tech advance for 12 or more months from now, or simply a mistake. I'm not seeing this feature in the 2023 Cadillac Lyric owners manual.

Given that an idiot light is apparently state of the art, it makes me wonder why the graphic is showing a % of life stat. Maybe part of an OnStar service rather than a car feature?
 

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Honestly, I think it would end up just being more trouble than a help. People that know what to do with code information often (bordering on always) already have OBD readers or intend to get them before they even have both metric and SAE wrenches. People that don't know what to do with the information behind the codes are going to need help and advice anyway, whether they get it from a forum, a manual or a dealership service department anyway.
I just don't want the mechanic to pull a fast one when all that may be needed is a new bulb.
 

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I just don't want the mechanic to pull a fast one when all that may be needed is a new bulb.
Unfortunately there's no such thing as "just needing a new bulb" with today's dashboards. These boards are complete printed circuit boards and the bulbs, if any, are soldered onto them.
 
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I just don't want the mechanic to pull a fast one when all that may be needed is a new bulb.
What you're basically asking for is the service manual. Which is fine, I'm in favor of everyone who wants one having a copy of the service manual for their vehicle, however obtained. But that doesn't need to be onboard, nor are 98% of owners going to even want it. They want what they critically need to know, no more, but often it takes years of analysis and interaction to parse out the important consequences and figure out what someone DOES need to actually know.

EG: The Volt has been out for over a decade. Only in the past (what would you say, Steverino? obermd?) two years have we learned that when the CEL comes on, the car pops up a message saying "Propulsion Power Reduced" and the generator starts screaming up to about 4000 RPM that the critical thing to NOT DO is immediately pull over and turn the car off. Because on page 4427 of 8110 in the service manual is part of DTC P0AFA, subsection Action Taken When the DTC Sets, it says:

• DTCs P0AFA and P0AFB are type A DTCs.
• If any of these DTCs are set, the vehicle will operate in a reduced power mode and charge sustaining mode.
Once Vehicle Power has been turned OFF all of the contactors will be prevented from closing. [emph mine]

Which means (probably anyway, now that we've had 10 years looking at it) that one battery cell group is critically low, the car is desperately running the generator trying to charge it up, the DTC may clear when it is charged up enough, and if you turn the car off before that charging up happens, the car will disconnect the main battery and you'll need to be towed to a dealership to get it unlocked. So your best course of action is to drive straight to your dealership anyway so they can just push it into a service bay when they have one. It's in the manual, but it takes a long time to find it and suss out what it means.

So what does that mean for the EQ? That DTC is probably going to be in there, in some form, somewhere in another 8000 page manual. A code that says a battery cell in one of the Ultium modules is way out of line with the others, and what happens when that condition exists is going to need to be puzzled out so that owners know the best way to handle the condition: is the car going to recover with charging? Is it going to disable the whole main battery? Is it going to lock out a module? Half the modules? The whole pack? We'll need to sort that kind of thing out. As a community and with reports from people experiencing problems so we can read an index and find the page where it says "battery will be disabled if you turn off vehicle power" and tell people "if this happens when it 'shouldn't', then DO NOT TURN OFF POWER, drive to someplace safe with plenty of room in front of you for a tow truck before you turn it off." Or whatever it is for whatever condition that comes up.

But putting that in a display in the car isn't feasible.
 

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But that doesn't need to be onboard, nor are 98% of owners going to even want it.
Heck, from what I see, 98% don't read the Owners Manual, even when the answer to the question they have is in there!

I do think having the actual error codes display in a submenu would be nice for those who care to then look them up to get an general idea of what the issue might be.

Here are the Volt DTC's (Diagnostic Trouble Codes, aka Fault Code or error code) to give an idea of what these look like:
11OBDG01 HYBRID Diagnostics Part 1.pdf
11OBDG01 HYBRID Diagnostics Part 2.pdf
 

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Another item would be the 12v battery health. In an ICEV you can detect a weakening battery by the car's willingness to turn over when starting. In an EV where the 12v battery is used just to power up the computers and other low voltage electronics it's not so easy.
 
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Another item would be the 12v battery health. In an ICEV you can detect a weakening battery by the car's willingness to turn over when starting. In an EV where the 12v battery is used just to power up the computers and other low voltage electronics it's not so easy.
We at least think we've got that one figured out. Volt had a 12v AGM aux battery, Bolt has a 12v AGM aux battery, Hummer EV has a 12v AGM aux battery, and testing that battery is going to need internal resistance checks, not "cold-cranking amps", just like those other vehicles do too.
 
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