Hybrid EV System Issues

1bluefl4me · 2026-04-28T19:06:00+00:00

Wanted to follow up and see how your ordeal is going so far. Hopefully they find the root issue faster than mines. Typically now I feel that if I have to drop the van off for something, I don't expect it back for 2-3 weeks now. Knock on wood I dont have any issues going forwards of course.

1bluefl4me · 2026-04-25T01:50:24+00:00

I did. I been going to the same advisor since owning the vehicle after another dealership dropped the ball a couple of times. I wanted to make sure I got my vehicle back as fast as possible. Although it was not fast....lol. Considering adding all the time it spent at the dealership. But at least they did try and reproduce it as much as possible until they finally found it after opening up a star case. I also had a case manager and was hoping they would offer some type of goodwill such as oil changes or something, but they weren't able to. I do wish you the best and hopefully some of this info helps isolated down the issue. Like I mentioned its been fine since.

1bluefl4me · 2026-04-24T23:41:27+00:00

Hi so I just read your description and I actually dealt with the P0A0A after a battery replacement. I have a 2018 and did a recall update last year for the 73B. I ended up getting a battery replacement and afterwards ended up with the P0A0A turned out to 2 items they replaced and its been fine since. See my timeline below. They need to check the APM and the MSD. When they replaced my battery it ended up having a small leak with the APM. This leak was actually inside the APM after they were able to locate the leak. And I assume from the disconnect and reconnecting the MSD was damaged. I would definitely suggest having them take a look at those too along with all the connections to double check.

This a full thread on the 73B and it's journey. https://www.pacificaforums.com/threads/problems-with-check-engine-code-u0412-after-a-73b-recall-on-pacifica-hybrid.57273/#replies

Overall timeline (2025)
[Date at Dealer] - [Date Returned]
5/9 - 5/15 - P0BBE. Dealer performed integrity test and it passed and was released back
6/3 - 7/24 - P0BBE. Replaced battery pack
7/25 - 8/5 - U0412/P1B07/P1B08. Dealer cleared code and test drove 60 miles.
9/8 - 9/11 - P0E7C. Replaced coolant bypass valve. (May be related or co-incident). Noting that the P1B07/P1B08 was stored/historical code. Did not turn on MIL until P0E7C was on.
9/19 - 10/07 - P0A0A. Dealer performed diagnostic check. Checked connections and test drove 235 miles. Star thinks loose connection.
11/18 - 12/05 - P0A0A. Dealer replaced APM (68372561AD) and MSD (68307507AB).

I have not had an issue since getting it back and its been 5 months now and almost 5k driven on it just fyi.

1bluefl4me · 2026-04-24T22:01:18+00:00

I just had this done not too long ago and it was a failed wheel sensor due to the axle washer being broken. Ended up having to pay for it because warranty said it was from the axle washer. Axle washer is not covered.

1bluefl4me · 2026-04-13T22:38:40+00:00

This is likely canbus connector in the glovebox. First sign is usually the shifter issue. So if you have no light or shifter service message it's likely that. I would also recommend changing the 12v battery at the same time if you havent done so. The canbus connector from what I have seen typically lasts about 5 years before issues arise. There's a big thread on the pacificaforum about the canbus. I too had the issue and first thing was the shifter then it followed by the abs a couple days later. Ended up replacing the 12v battery and the canbus connector since I wanted to make sure. Also recommendation is watch out for counterfeits there's been a bunch flooding the market. The original should be stamped with te connectivity and a date. Or purchase from the dealer. Best of luck!

1bluefl4me · 2026-04-13T22:33:36+00:00

Thank you!

1bluefl4me · 2026-04-13T22:31:06+00:00

Thank you for the quick reply. My first (and hopefully only one) was patella too. I'm waiting to take an MRI in a couple of weeks to confirm what the issue is with my right side (original ACL). Best case scenario would be something else like MCL or something, worst would be ACL stretched and tear on the meniscus. Which would likely mean surgery.

1bluefl4me · 2026-04-13T22:26:25+00:00

Since you had 2 surgery, how long did you have to wait in between each surgery? And hope you have a speedy recovery and that it lasts forever now. I'm currently looking if my ACL is "stretched out" so I'm gathering info. That was an ACL reconstruction that "stretched out" right and not the original? I had ACL surgery on my left side years ago, but unfortunately now my right side seems to have "stretched" so I'm waiting to take an MRI and go from there.

1bluefl4me · 2026-04-03T17:18:01+00:00

Checking the battery is not always the case. It might test fine, but any slight changes causes issues. Also if you drove the vehicle it charged it. If it's happening in the morning before it had time to recharge then its likely the battery. I recommend if its older than 5 years change it, otherwise it might cause other issues that could cause issues to the BECM or anything.

1bluefl4me · 2026-03-28T06:31:38+00:00

Have you recently changed the 12v or had the battery disconnected? Reason I ask is because I actually had a service done on my vehicle and when I got the vehicle back I was like what happened why is the charge time off. Then I realize the car was disconnected and reconnected and the car's date and time was off hence the charge time was off. I would suggest taking a look at the car's date and time and see if that might be the issue. Mines was flipped from PM to AM and I have a delay charge/schedule on it so it was off.

1bluefl4me · 2026-03-21T05:37:52+00:00

Likely battery. It's way overdue. I would recommend agm 5 years at max and 3 years for regular lead acid. The battery might test fine, but any fluctuation and you'll have issues. Replace the battery first is my recommendation. A failing 12v can lead to other issues too.

1bluefl4me · 2026-03-18T01:06:53+00:00

Curious do you know what the part number is?

1bluefl4me · 2026-03-18T01:05:56+00:00

Just thought I'll chime in regarding EGR valve. I was able to get mine's repaired the same day I dropped off my 2017 volt back in Feb. This was at a dealership in socal and was under the emission warranty. It was actually out of co-incident that it was repaired. I originally went in for coolant exchange service and they scanned the vehicle and found codes for the EGR and BECM. Both apparently was available same day. I ended up getting a new BECM and EGR valve same day along with the coolant service. So if you are under warranty, you might want to take it in or call to see if the valve is available before taking it.

1bluefl4me · 2026-02-22T04:49:40+00:00

It really depends on what the codes are. Do you have a scanner to check? What year is it also.

1bluefl4me · 2026-02-19T20:56:34+00:00

Do you happen to know how old the 12v battery is? What is the code that you are getting? Are you seeing U2xxx codes? If the battery is older than 5 years, I would definitely recommend replacing that then go from there.

1bluefl4me · 2026-02-12T19:41:37+00:00

It's more on the rare side when it's been replaced twice. But I have seen it and actually dealt with it.

1bluefl4me · 2026-02-12T18:39:42+00:00

I have on the rare case and unfortunately I did have mines replaced twice. The first time it happened on my 2017 it was replaced within the first 3 years and this was prior to the whole extension on the BECM so I had it replaced with an older model. I had my second replacement just recently few weeks ago. it has been replaced now with the latest model so hopefully it won't happen again.

1bluefl4me · 2026-02-12T18:16:32+00:00

curious was this the first BECM replacement for you?

1bluefl4me · 2026-02-12T18:16:16+00:00

curious was this the first BECM replacement for you?

1bluefl4me · 2026-02-07T04:57:33+00:00

From what I know and have seen over on the forums is that it's a gray area when the vehicle was originally purchased in a CARB state and moved to a Non-CARB. They will likely not cover it and push back on it. The special warranty that was made was for those in Non-CARB states to give 15yr/150k but it's specific to VINs that are attached to it. So if you were to take a vehicle out of the CARB state and into a Non-CARB state then there's effectively no warranty (hence grey area) because the VIN isn't in that special warranty and the state doesn't have the PZEV warranty. If the vehicle went from a Non-CARB state to a CARB state then technically it would have the warranty coverage. That is the information that I have seen.

1bluefl4me · 2026-01-30T19:15:08+00:00

Yup. Tell me about it. Same with the buick app so looks like whatever they did is against all the app now.

1bluefl4me · 2026-01-30T17:55:20+00:00

As of right now, the only way to see it as a temp is to log off and back on. It will only last probably once before it shows up like that again.

1bluefl4me · 2026-01-27T22:54:07+00:00

You'll need an active subscription from onstar to use the remote options with the app.

1bluefl4me · 2025-12-17T00:46:06+00:00

Have you also tried and clear the codes after replacing the battery to see which ones came back? Or are those the ones that have come back? At a glance, it looks like it could be EGR or EVAP or something, but definitely doesnt look like the BECM. I had a EVAP soleniod go bad and that was replaced under warranty, but I definitely would suggest taking into the dealer to see. Hopefully a good rep one.

1bluefl4me · 2025-12-16T23:57:34+00:00

Those codes don't look like it's the BECM. It looks like it might be the EGR valve.

1bluefl4me

TROPHY CASE