"Service High Voltage Charging System" Fix (Updated) + VCX Nano Setup Guide (VX Manager, ACDelco TDS, Techline Connect, SPS2)

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bit1817

Discussion Starter · Nov 8, 2021 (Edited)

The “Service High Voltage Charging System” message is a common problem on first generation Volts. Often, the only way to fix the error is to reprogram the BECM and HPCM2 modules (even if nothing is inherently wrong with the vehicle). Before you reprogram the modules, you should see if clearing the codes fixes the issue. Also, make sure the battery coolant is not low. If clearing the codes does not permanently fix the problem, you most likely need to reprogram the modules. This can be accomplished by purchasing a VCX Nano and SPS2 subscription from ACDelco TDS.

GM recently discontinued SPS and replaced it with SPS2, so many of the guides are outdated. I recently reprogrammed the BECM and HPCM2 modules on my Volt and made a video and guide. Hopefully, it will be useful for anyone with the same problem.

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mitchtheriault

· #121 · 2 mo ago

Volusiano said:
Thanks for more details on this. When you said that the battery had been exclusively maintained by the gas engine during those 2 years, did you mean that you ran in Mountain Mode during those 2 years to build up the 40 or 50% battery reserve and keep running in Mountain Mode each time to avoid the battery from discharging? Or did you build up the reserve, then ran the battery down, then built up the reserve again? Or did you just leave the battery at the depleted state of charge and just ran on gas the whole time? If the third scenario, then maybe leaving the battery depleted all that time might have been hard on the battery and messed up some cell(s) like you suspected.

Have you had the recall # N172130462 done? I think it's a reprogram of the HPCM2 module to rebalance battery cells properly again to avoid the low propulsion error message. So maybe this reprogram of the HPCM2 that you just did now has the update from that recall included. So if it does, hopefully your bad battery cells may eventually get balanced out eventually after a while and you'll no longer get the intermittent grayed out battery issue that you now have.

Nah, I hardly use mountain mode. I just drove it in the normal gas mode, which would maintain the battery at 10-20% I believe? The car is at about 300,000km, and I haven't babied it at all.

Yeah, I had that recall done a few years back. If I recall correctly, that's the one that decreased the amount of usable battery capacity.

Ender

· #122 · 2 mo ago

Holy moly,
so you left the battery drained for 2 years! That should safely kill a usual "LiPo" but i do not know the chemistry & durability of the quite exotic Volt battery.
Also hard to say how empty "empty" really was. For sure it started out at the usual 30-ish % but then self darin vs. recuperation ?! I have no idea tbh how charge state held up.

Keeping fingers crossed for you that it comes back to life.

MyGreenVolt should show you cell voltages as a hint.
Also MyVoltCapacity might give a hint about the batteries state. But first you should give it some full charge / discharge cycles. If i were you i would always do full charges for now, no partial charges.

Good luck!

Ender

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Old_Cranky_Paladin

· #123 · 2 mo ago

Trying my second reboot of the HPCM2, according to the guide. I did it once 6months ago. Still have my techline account, but techline will not install “MDI2”. Keeps failing and asking to run it as “admin”. I am running the program as admin (via properties > accessibility) but “running as admin” from the techline website doesnt start up techline. I have rebooted and tried reinstalling techline.

Any advice?

Using a windows 7 empty sacrificial laptop with vcx nano.

Thanks,
Cranky Paladin

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3

Ender

· #124 · 2 mo ago

Old_Cranky_Paladin said:
...

Using a windows 7 empty sacrificial laptop with vcx nano.

...

Hi there!
Not having tried with Win 7 it nevertheless could be that the really mean it when saying that Windows 10 is a requirement.
You can always try that in a VM if you do not want to upgrade your main system.
I would do all this stuff in a VM anyways because of the zillion virus / malware warnings.

Good luck!!!

Ender

Volusiano

· #125 · 2 mo ago

Old_Cranky_Paladin said:
Trying my second reboot of the HPCM2, according to the guide. I did it once 6months ago. Still have my techline account, but techline will not install “MDI2”. Keeps failing and asking to run it as “admin”. I am running the program as admin (via properties > accessibility) but “running as admin” from the techline website doesnt start up techline. I have rebooted and tried reinstalling techline.

Any advice?

Using a windows 7 empty sacrificial laptop with vcx nano.

Thanks,
Cranky Paladin

I would concur with @Ender that you should probably try to create a VM that has Windows 10 inside and run it from there, assuming that the VMWare stuff can be built inside your Windows XP program.

As for the Techline Connect installation issue, I don't remember running into an installation error in the first Techline Connect original launch that told me I needed to run as admin to install, however, I remember seeing some error messages during the Techline Connect 2nd launch where it tried to install some follow-on updates to some of the modules already installed the first time. But then upon the third launch of Techline Connect, it went through cleanly into the interface as if all the modules had been updated successfully on that second launch.

Old_Cranky_Paladin

· #126 · 2 mo ago (Edited)

Thank you. I figured that would be my next attempt. I used a vm on a win10 machine last time. I was just trying to save some time since I had this old win7 laptop that can be sacrificed.
Thank you for the replies, I will probably try again the next nice weekend I have.

My volt is 2012 with almost 200k miles, I bought it used, and thought I would take the chance on it. Its current issue that caused this last failure was not being able to switch over from ev to gas one time. It was rough diagnosed as a failure of the shift selinoid. I already have a 2 year sub to techline and dont really want to invest alot more money into this car, especially to train the local dealers on how to fix it. None of the small shops will deal with “high voltage” systems, and the dealers want “4-5 @ $150/hr” to diagnose the problem. So, I figured ill just do another reset, much cheaper, and see how it goes from there.

thanks guys!

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hellsop

· #127 · 2 mo ago

Ender said:
Holy moly,
so you left the battery drained for 2 years! That should safely kill a usual "LiPo" but i do not know the chemistry & durability of the quite exotic Volt battery.
Also hard to say how empty "empty" really was. For sure it started out at the usual 30-ish % but then self darin vs. recuperation ?! I have no idea tbh how charge state held up.

The driving it around on Charge Sustain (hybrid) mode would have protected the battery from any self-drain, by having the engine start at about 3.5% usable state of charge and charge back up to about 5%. I'm not 100% sure where this maps in actual SOC, but it's likely 22-25% actual. Low, but not damaging. (Gen 1 Volts only use about the middle 60% of the battery charge (Gen 2 goes to almost 80%), and call everything between 20% and 80% "100%". THAT'S the majority of how Chevrolet manages to get thousands of cycles out of 2010 chemistry...

)

MyGreenVolt should show you cell voltages as a hint.

Be aware that MGV mostly reports the usable SOC percentages, with the top and bottom unusable capacities already removed.

Ender

· #128 · 2 mo ago

hellsop said:
The driving it around on Charge Sustain (hybrid) mode would have protected the battery from any self-drain, by having the engine start at about 3.5% usable state of charge and charge back up to about 5%. I'm not 100% sure where this maps in actual SOC, but it's likely 22-25% actual. Low, but not damaging. (Gen 1 Volts only use about the middle 60% of the battery charge (Gen 2 goes to almost 80%), and call everything between 20% and 80% "100%". THAT'S the majority of how Chevrolet manages to get thousands of cycles out of 2010 chemistry... )

Be aware that MGV mostly reports the usable SOC percentages, with the top and bottom unusable capacities already removed.

Well, i sort of hoped that, i mentioned those "30-ish" percentages but so it was more "20-ish"

For MGV i meant that tab that shows voltages of individual cells, NOT capacity.
If you would drive after full charge & equalize and one or more of the cell voltages would go down much harder than the rest that would be s source for grief IMHO.

Ender

hellsop

· #129 · 2 mo ago

Ender said:
Well, i sort of hoped that, i mentioned those "30-ish" percentages but so it was more "20-ish"
For MGV i meant that tab that shows voltages of individual cells, NOT capacity.
If you would drive after full charge & equalize and one or more of the cell voltages would go down much harder than the rest that would be s source for grief IMHO.

That is the case. And we know that 140mv difference is where the car starts spitting errors and going into Propulsion Power Reduced mode, and you should not turn the car off while that's happening And instead, let the generator catch up a bit. If you power down the car while in crisis, the car will disable the main battery and make the car undrivable, then require service tech intervention to clear the condition and reenable the battery.

And MGV has a total-pack usable percentage readout on the default dashboard display.

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Volusiano

· #130 · 2 mo ago (Edited)

hellsop said:
That is the case. And we know that 140mv difference is where the car starts spitting errors and going into Propulsion Power Reduced mode, and you should not turn the car off while that's happening And instead, let the generator catch up a bit. If you power down the car while in crisis, the car will disable the main battery and make the car undrivable, then require service tech intervention to clear the condition and reenable the battery.

What does the text highlighted in bold above entail? How long should we wait before turning off the car then? What would the criteria be to feel safe enough to turn off the car? Or should we put the car in Mountain Mode to let the car build up the 40 or 50% charge on the battery before turning off the engine then, even if we have already arrived at the destination? Thanks!

MikeBCo

· #131 · 2 mo ago

it means let the engine run long enough that it shuts itself off without your intervention.

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Volusiano

· #132 · 2 mo ago

MikeBCo said:
it means let the engine run long enough that it shuts itself off without your intervention.

Thanks, @MikeBCo! Any other situation beside the Reduced Propulsion Power warning when you need to heed this? No reply is needed if not. Thanks again.

MikeBCo

· #133 · 2 mo ago

I guess it depends on whether you are suspecting your battery is getting unhealthy... I rarely drive far enough to get to the bottom of my battery. I have never seen a PPR message (in fact my Volt seems to happily provide over 140 kW of output mysteriously - see recent thread). However, since I live in a higher elevation area and have a steep driveway, if I have reached the point where the engine is running, once I get home, I make sure I let it continue to run to get a chance to catch up and get the battery charged to the minimum prior to shutting down. If the battery is empty, typically I will also go ahead and tell the Volt to charge immediately just because I don't want it to sit at too low of a charge overnight waiting for delayed charging to start.

Ender

· #134 · 2 mo ago (Edited)

Hmm, we often exceed battery charge and for us i believe we see the PPR message not because of cell difference > 140mV but because of a drop of SOC below a certain minimum so the car does not want to deplete the battery further and guarantees that "for now" the combustion engine will solely power the drivetrain AND even invest a share for charging up the battery above that magic limit again.
Most often i saw PPR when driving until battery was empty, then shutting down the car when temperature was going down. Like stopping the (empty or near empty battery) car when it was 7° Celsius and THEN starting the car with e.g. 0° Celsius.
So because of the drop in temperature the SOC "felt" like it spiked down and the car then took the PPR measure to get all good again.

I did not monitor it but i would BET that we had some occasions (That short drive home) when we finally stopped the car with PPR still active.
But i sincerly do not know. Unless you suspect that PPR could result in something bad you would not monitor this.

So i hope that the car will only be stuck (if turned off while PPR still active) if there was a PPR due to high cell difference and not just because the battery level went below a critical limit.

Does that make any sense to y'all?

Ender

P.S. lots of typo & BS edited, i am pretending to work while i wrote this, sorry

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hellsop

· #135 · 2 mo ago

Ender said:
Hmm, we often exceed battery charge and for us i believe we see the PPR message not because of cell difference > 140mV but because of a drop of SOC below a certain minimum so the car does not want to deplete the battery further and guarantees that "for now" the combustion engine will solely power the drivetrain AND even invest a share for charging up the battery above that magic limit again.

That's exactly my conviction as well. There's other weird compensations that happen that monitor the drawdown of battery versus capacity and do ... unexpected and unannounced things to accommodate. (There's several reports of cold-weather but not ERDTT-zone engine running when the car is moving quickly and the car (apparently?) decides it needs to supplement or mitigate the load to run the battery heater or something. I've seen it happen myself, but haven't worked out all the criteria yet.)

Most often i saw PPR when driving until battery was empty, then shutting down the car when temperature was going down. Like stopping the (empty or near empty battery) car when it was 7° Celsius and THEN starting the car with e.g. 0° Celsius.
So because of the drop in temperature the SOC "felt" like it spiked down and the car then took the PPR measure to get all good again.

We've long known about people leaving the car with a little charge left and come back to it later and those miles/km were just gone and the car started in Charge Sustain/hybrid mode. This sounds similar enough that it may be related.

Ender

· #136 · 2 mo ago (Edited)

hellsop said:
...
We've long known about people leaving the car with a little charge left and come back to it later and those miles/km were just gone and the car started in Charge Sustain/hybrid mode. This sounds similar enough that it may be related.

Yes that part is 100% confirmed to me although annoying at first i can now reason for it.
I also have seen the opposite now a lot of times, leaving a car alone in the early morining hours and seeing higher range left when i turned it on after a steep temperature rise.

Ender

Volusiano

· #137 · 2 mo ago

hellsop said:
If you power down the car while in crisis, the car will disable the main battery and make the car undrivable, then require service tech intervention to clear the condition and reenable the battery.

Thanks @MikeBCo and @Ender and @hellsop for sharing your views on the Propulsion Power Reduced situations. Everything you guys said make sense to me.

I guess I'm still worried about the particular bit above that was mentioned by @hellsop , so I want to dive more into this mention and maybe phrase the question from a different angle: -> "What are the specific conditions that can cause the Volt to disable the main battery that would require a service tech to clear the code and re-enable the battery again?" We know that perhaps PPR due to cell imbalance may cause this. But what else can cause this that we need to heed?

Also, if the car disables the main battery, it can still be driven using the ICE, no? At least to take the car to get it serviced to re-enable the battery. Or does it really make the car undrivable altogether and need a tow to a dealership?

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hellsop

· #138 · 2 mo ago

Volusiano said:
Thanks @MikeBCo and @Ender and @hellsop for sharing your views on the Propulsion Power Reduced situations. Everything you guys said make sense to me.

I guess I'm still worried about the particular bit above that was mentioned by @hellsop , so I want to dive more into this mention and maybe phrase the question from a different angle: -> "What are the specific conditions that can cause the Volt to disable the main battery that would require a service tech to clear the code and re-enable the battery again?" We know that perhaps PPR due to cell imbalance may cause this. But what else can cause this that we need to heed?

As far as we know, P0AFA and P0AFB are the only codes that do that. I don't think we've ever seen a P0AFB code (which is the same thing but HIGH voltage instead of low), so I'm not going to mentioned it again even though it technically counts for a lot of this. It may be important to note that the PPR event isn't what causes the "battery contactors not allowed to close to connect the battery" circumstance, it's the P0AFA code. We don't know that the P0AFA code will go to a historical (not active) state on its own, and allow the car to be shut down without it locking out the battery, but we know that shutting the car down immediately WILL lock out the battery. But many other codes that are state-dependant like this do go historical, so we hope.

Also, if the car disables the main battery, it can still be driven using the ICE, no? At least to take the car to get it serviced to re-enable the battery. Or does it really make the car undrivable altogether and need a tow to a dealership?

No it cannot. It cannot be charged or driven. It will turn on, in Service Mode, and appear that everything is fine, but the car will not move. The only SURE thing we know to do if P0AFA has happened is to drive to your dealership park someplace convenient for the porters to push the car into the service area and call a taxi to get home. We HOPE that if the engine can be allowed to stop on its own that that will resolve the P0AFA. We also know that not waiting disables the battery.

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Volusiano

· #139 · 2 mo ago

hellsop said:
As far as we know, P0AFA and P0AFB are the only codes that do that

This is very valuable info to learn from, thank you so much to take the time to explain the details, @hellsop! But pease allow me to follow up with some more questions if you don't mind.

Usually messages like the PPR stuff, or the SHVCS stuff, show up on the dashboard display in full text, but I don't recall ever seeing an error code per se on the display. For example, when I got the SHVCS error on the display, I had to connect an ODBII to the car and use the Torque Pro app on my Android phone to scan the fault codes to see what they were (associated with the SHVCS error on the dashboard display), like POAA6, P1E00, P1FFF. So how would I know that the car is throwing the P0AFA code is it's not showing on the dashboard? What kind of error text message would I see on the dashboard that would be associated with P0AFA and P0AFB per se?

Also, can this P0AFA fault be cleared via an app like the Torque Pro (or whatever else) via the OBDII connector? Pretty much in the same fashion as the 3 faults for SHVCS can be cleared so that you can charge the car again, at least until the next time the car throws up the fault codes again, or until you remedy the issue with the reprogram of the HPCM2 and BECM? I'm thinking that you probably can't clear it as easily just because it sounds so much more serious because the car is now disabled, but it's worth asking, I guess.

Along the same line, beside doing a temporary fault clearing like with the SHVCS issue so you can get the car running again which may not be possible, can you also DIY to replicate whatever the service tech guy would do at the dealership to get the car running again due to the P0AFA code, if you already have a ACDelco TDS subscription to run Techline Connect via the VCX Nano, along the same line of reprogramming the HCPM2 and BECM modules to fix the SHVCS error for good? Thanks!

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hellsop

· #140 · 2 mo ago

Volusiano said:
Usually messages like the PPR stuff, or the SHVCS stuff, show up on the dashboard display in full text, but I don't recall ever seeing an error code per se on the display. For example, when I got the SHVCS error on the display, I had to connect an ODBII to the car and use the Torque Pro app on my Android phone to scan the fault codes to see what they were (associated with the SHVCS error on the dashboard display), like POAA6, P1E00, P1FFF. So how would I know that the car is throwing the P0AFA code is it's not showing on the dashboard? What kind of error text message would I see on the dashboard that would be associated with P0AFA and P0AFB per se?

You'll get a check engine light, maybe flashing (I don't know if I've read someone saying), and the PPR. That's it. What the code actually is needs an OBD reader to determine.

Also, can this P0AFA fault be cleared via an app like the Torque Pro (or whatever else) via the OBDII connector? Pretty much in the same fashion as the 3 faults for SHVCS can be cleared so that you can charge the car again, at least until the next time the car throws up the fault codes again, or until you remedy the issue with the reprogram of the HPCM2 and BECM? I'm thinking that you probably can't clear it as easily just because it sounds so much more serious because the car is now disabled, but it's worth asking, I guess.

It cannot. You need to do the Clear Secured part before the P0AFA will go away entirely. The thing we don't know is whether the removing the conditions for setting the code (a drastically low cell or pack voltage) will move the code from active to historical or if there's no hope at all.

Along the same line, beside doing a temporary fault clearing like with the SHVCS issue so you can get the car running again which may not be possible, can you also DIY to replicate whatever the service tech guy would do at the dealership to get the car running again due to the P0AFA code, if you already have a ACDelco TDS subscription to run Techline Connect via the VCX Nano, along the same line of reprogramming the HCPM2 and BECM modules to fix the SHVCS error for good? Thanks!

If you HAVE all the gear set up that you can do the "Clear Secured" part yourself, then you can do it. I think that's all the stuff that's needed.

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