[giveusroom]

I've had my Volt for a month and it's been fantastic. However, my check engine light came on last night. I did not notice any other symptoms and the Volt drove home just fine. The closest authorized Volt dealer (at least with any experience) is 90 miles away. Can I get a code read by using On-Star? Is it OK to ignore this for a few days to see if it goes away? Any advice?

 

[Stilgar99]

Dont ignore it. Use Onstar asap to have the tell you the exact 'diagnostic code'. (get the exact number so that folks here can help you). The Onstar advisor may tell you to go straight to your dealer. I would check here first (some code are not that bad...and some even seem to reset), however I would advise you do not drive the car much until you get more data.
Once you get the code, post it here and folks may help if they have even seen it before....

Stilgar

 

[giveusroom]

I talked to On Star. The code is P0D22 - Battery Voltage Sensing Error. They advised me that I might not be able to charge the Volt. Not true. The Volt charged just fine. I don't notice anything wrong. I think it was a voltage measurement glitch. One thing I did do a couple of times is unplug the Volt after it was fully charged and then plugged it back in immediately. Makes me wonder if this caused the glitch. Anybody know anything about this code?

 

[Slapshot28]

I had the exact same thing happen, from the exact same cause (unplugging/replugging with full charge, 120V connection).

Unless GM says otherwise, you are okay and the CEL should turn itself off after 2-3 days. It is a bit disconcerting, but at least we know the car is being sensitive!

Since then I've just left the Volt plugged in at all times, unless I'm ready to go!

Chris

 

[WopOnTour]

I talked to On Star. The code is P0D22 - Battery Voltage Sensing Error. They advised me that I might not be able to charge the Volt. Not true. The Volt charged just fine. I don't notice anything wrong. I think it was a voltage measurement glitch. One thing I did do a couple of times is unplug the Volt after it was fully charged and then plugged it back in immediately. Makes me wonder if this caused the glitch. Anybody know anything about this code?

DTC P0D22 is actually titled: Battery Charger Output Current Performance. Typically it would be detected and set during charging it should first A) temporarily disable charging (until the next charge cycle) and B) brings on the Check Engine Lamp (MIL) on the next drive cycle.

Basically P0D22 indicates that during the charge, the measured charging current was not within certain parameters over a defined period of time. If your Volt appears to be charging normally then the fault is no longer present.

I am wondering about the repeated disconnects-reconnects though. I suppose it might have created a false fail somehow. If it sets again you'll definately want to take it to your dealer.

WopOnTour

 

[giveusroom]

I did a search and found the other thread about CEL codes and specifically this code that Chris had. It makes me suspect an unanticipated scenario by the developers with this error - plugging in when Volt is fully charged. That might cause the charge current to never reach the expected levels within the 40 seconds and an error is flagged, but the reality is that the Volt is simply fully charged. There needs to be a check on the voltage before flagging the error. If the voltage is above a certain threshold, the error should not be flagged. Or perhaps that is already done, but the threshhold needs adjustment. Or maybe I'm way off.

 

[WopOnTour]

I did a search and found the other thread about CEL codes and specifically this code that Chris had. It makes me suspect an unanticipated scenario by the developers with this error - plugging in when Volt is fully charged. That might cause the charge current to never reach the expected levels within the 40 seconds and an error is flagged, but the reality is that the Volt is simply fully charged. There needs to be a check on the voltage before flagging the error. If the voltage is above a certain threshold, the error should not be flagged. Or perhaps that is already done, but the threshhold needs adjustment. Or maybe I'm way off.

I agree. There might also be an issue with the enable/fail criteria as documented in gSI.
But my understanding was when the charging was in voltage regulation mode (initially and during the finish of charging) the P0D21 would set if charging voltage wasnt correct, but when in current regulation mode (during the majority of the charge cycle) then P0D22 sets if measured charging current was not correct. (a you said for 40 seconds)

I've unplugged and plugged in the car while charging AND when fully charged (both repeatedly) and never had this DTC set falsly, but it might still under very specific conditions that we've yet to define. If it is false it's nothing that software can't rectify of course, so that's why I'd suggest a dealer visit (if not TOO inconvenient) even if it doesnt reset as it needs a case# to get something happening.Plus there should be a Freeze Frame that would indicate the conditions present when the fault was detected.

But there's also a recent (since SOP) update for the onboard charger control module listed in TIS2WEB. It's titled "OBD II diagnostic software and calibration changes". I'll try and find out exactly what it specifically addresses but if you took it to the dealer they could easily determine if you have this update already.
HTH
WOT

 

[giveusroom]

Thanks to all of you for responding on this thread. This forum is golden for Volt owners. Thanks WOT.

 

[Chevrolet Customer Svc]

Wanted to let everyone know that it is not necessary to bring a Volt to a dealer with a P0D22 code at this time, as long as there are no charging complaints.

Thanks,
Caron - Chevrolet Volt Advisor
[email protected]

 

[giveusroom]

My CEL went out today. Car is fine. No problems with charging at any time, including when the light came on. Again, thanks for the information and advice. I love my range extended electric car.

 

[agsdoc]

Received a call last evening from GM conducting a survey of Volt owners to see if any problems have arisen so far. None had at that time. However today the engine light went on. I called On Star who informed me that it was a P0D22 error. They called the dealer, made an appoint for me for tomorrow morning. Came home and checked this thread. I called a Volt Advisor, asked them to confirm that I wouldn't have to take it in, which they did about an hour later with a return call. Thanks to all the posts on the thread as I was able to give the Volt Advisors the correct info and you saved me a trip to the dealer. Does anyone know if a software fix is on the way?

 

[ClarksonCote]

My Volt recently had seven "control modules" upgraded (software)... I suspect one of them addresses this Voltage sensing error sensitivity.

 

[Xzlon]

My Volt recently had seven "control modules" upgraded (software)... I suspect one of them addresses this Voltage sensing error sensitivity.

Who recommend or identified the modules to be upgraded. Or was it just done during scheduled/unschedule a trip to the dealer?

 

[WopOnTour]

Who recommend or identified the modules to be upgraded. Or was it just done during scheduled/unschedule a trip to the dealer?

Generally, unless your Volt is exhibiting some sort of negative behavior or "symptom" there will be no need for routine visits for software updates. Information is provided to dealerships as to important software updates via an internal Technical Service Bulletin (TSB) system, and will typically be addressing specific concerns/complaints.

More critical updates would either be made part of a GM campaign (aka "recall") or if deemed necessary dispatched utilizing the new Over The Airwaves (OTA) update system via Onstar, however this OTA system is still in early development stages. The reliability of programming via OTA is very much dependant on a "stabilized" vehicle condition that will require customer cooperation in order to be successful (they absolutely can't just "reflash" one of your modules while you are "just driving along" on the Interstate.)

I've been monitoring the release of updates as well as TSBs that are released indicating an update might be required across a large segment of the current Volt population, and to-date there is nothing "critical". (My plan would be to have an official "Volt TSBs" thread created at some point/time to better support this)
However IF your Volt has been setting DTCs or has any other sort of operational complaint, a dealer visit will certainly prompt the software levels to be scrutinized sufficiently to deal with the concerns, should a revision exist.

WopOnTour

 

[Stilgar99]

I've been monitoring the release of updates as well as TSBs that are released indicating an update might be required across a large segment of the current Volt population, and to-date there is nothing "critical". (My plan would be to have an official "Volt TSBs" thread created at some point/time to better upport this)
However IF your Volt has been setting DTCs or has any other sort of operational complaint, a dealer visit will certainly prompt the software levels to be scrutinized sufficiently to deal with the concerns, should a revision exist.
WopOnTour

A Volt TSBs specific thread would be great! (Should be read only for most).

Stilgar

 

[Rusty]

they absolutely can't just "reflash" one of your modules while you are "just driving along" on the Interstate.

Assuming adequate on-vehicle storage capacity, they could download an upgrade for modules while you are "just driving along" on the Interstate. They just shouldn't install them until the car is off, and preferably plugged in to indicate it's likely to stay off for a bit. An "upgrades available, proceed to install screen?" might be nice.

 

[WopOnTour]

Assuming adequate on-vehicle storage capacity, they could download an upgrade for modules while you are "just driving along" on the Interstate. They just shouldn't install them until the car is off, and preferably plugged in to indicate it's likely to stay off for a bit. An "upgrades available, proceed to install screen?" might be nice.

FYI That's exactly what "reflashing" means, installing them. Where they are sourced or temporarily stored is irrelevant IMO.
My point was the vehicle condition that must be present during the actual installation must be highly controlled.
Something that cannot be easily guaranteed or perhaps not ever occur without the owner/user cooperation I was referring to.
Wasnt saying there wasnt the potential to make it work, as obviously they already have...
WOT

 

[Mark Z]

The upgrades via OnStar could be initiated through the OnStar MyLink app. Since the app could be updated to provide user input and feedback, it might be an easy solution for those who do not want to visit their dealer.

OnStar knows when the vehicle is charging, so that could be a requirement to make sure that the Volt is not in use.

 

[WopOnTour]

My Volt recently had seven "control modules" upgraded (software)... I suspect one of them addresses this Voltage sensing error sensitivity.

I can confirm there are software updates available for a number of system modules for cars built prior to BU100954

These updates can be performed by your Volt dealer but are really only neccesary if very specific faults are being observed by the owner/s.

These include ANY of the following concerns,

Check Engine Light (MIL) or associated system warnings as a result of DTCs setting in any combination in the following modules:

Engine Control Module (ECM)- P0128 P0604 P06E4 P1133 P2181
Hybrid Powertrain Control Module 1 (HPCM1)- P07A3
Hybrid Powertrain Control Module 2 (HPCM2)- P0ABB P0604 P0D26 P0CD2 P0C4A
On-Board Battery Charger Control Module (OBCM)- P0D3E P0D3F P1F05
Accessory (14V) Power Module (APM) P1EA8 P1EA9
Intermittent Navigation Radio Reset and Rear Park assist volume concerns
ANY issues regarding operatonal concerns of the climate control system, (esp with respect to heated seats or fan blower functions)

Many thanks goes out to early adopters of the Volt for their asisstance in identifying these issues and their patience in helping their dealer and Volt technical assistance in determining root causes and reach final resolutions.

There is no subsitute for "real-world" experience!

HTH
WopOnTour

 

[ClarksonCote]

Thanks for the details WOT!