GM Volt Forum banner

2018 Battery Energy Control Module (BECM)

41851 Views 138 Replies 63 Participants Last post by  vap3
Hopefully this isn't a redundant thread but all I could find were threads on 2017 BECM failures.

I'm kind of curious how prevalent 2018 BECM failures are.

Mine occurred at 36,270 miles (300 after BtB warranty expired) and 3 weeks shy of 3 years.

Cruising at 30 mph, engine warning light came on. Battery charge level went from about 60% to 100% charge. Engine started. Shut down car and exited for about 30 minutes.
Upon restart, engine warning indicator remained illuminated (solid, not flashing) and charge indication was normal.
During 20 mile drive to shop, all normal (except engine fault indication).

5 fault codes (stored but inactive) indicating BECM. (I didn't get a list of the codes.)
Shop credited the $160 diagnostic fee. Parts available. Be at shop a couple work days.

1) The mechanic said that they've seen quite a few BECM failures for all MY gen 2s. Any other 2018 owners out there that have had failed BECMs?
2) Is it normal for a shop to replace (under warranty) an intermittently failed part, or is this just good shop?
3) I assume that the Battery cooling system fluid needs servicing after dropping the battery to replace the BECM. Does anybody know if they would flush it or just burp/service it? Is the BECM on the electronic cooling loop or the battery loop? If the former, same question about flush or service. (Obviously, I would hope for flush so I could zero time those loops.)

Thanks in advance for any feedback. (And moderators, if there are 2018 BECM threads or threads similar to this, please feel free to merge them.)

See less See more
1 - 7 of 139 Posts
I took a chance because I liked the idea of the Volt and I really do like the car but the company and their build quaility is at the bottom of the list. I have NEVER had any issues with a vehicle with this low of mileage.
Me too. My 2011 Volt was the first GM I purchased. However unlike you, I have found the car to be very well built. The few issues I have had have been minor. I do expect a main battery issue at some point, hopefully a few more years down the road instead of now.

My positive Volt experience convinced me to get the Bolt EV. That has been very good s well. GM just replaced the battery for free, I got an extra 29 miles range in the bargain, and the battery comes with a new warranty. Very delighted. Might end up replacing the Volt with a Chevy EQuinox (based on the Ultium battery platform). Given that the Ultium batteries will be used in almost all GM EV's and given it's designed to enable swapping out bad modules with those that may have new chemistry, I expect replacement parts to be more readily available including after warranty battery modules.

I agree that the dealer experience can vary from one to the next. I'm fortunate to have at least two good ones available, though they rarely see me. I think the supply chain issues are the root cause for the BECM replacement delays. Not that that is much comfort if your car is sitting waiting months for a part. And being a low volume vehicle does not help. Now if you had a Silverado...
See less See more
  • Like
Reactions: 1
GM seems to have miscalculated support for this vehicle.
This is bigger than one car manufacturer. The auto industry in general is having trouble getting replacement parts. You'll see similar complaints on Ford forums blaming Ford for long back order times on repair parts.

A caution to anyone who may need a car repair sometime soon: You may have to wait weeks, even months for parts, due to supply chain shortages that show no signs of letting up.
Matt Overbeck owns a repair shop, Overbeck Auto Services. "We are seeing car parts delays and shortages in some areas," he said. "Day, weeks, and in some cases months."

Besides catalytic converters, he says parts in short supply include:
ABS brake modules
Engine sensors
Transmission control modules

See less See more
Seems like more parts came in in April. Perhaps the supply chain is catching up a bit.
  • Like
Reactions: 1
I too have this problem on my 2018, 38k miles. The BECM is on order....3-4 weeks out. That was 9 days ago. Driving normal since, with CE light that goes out after charging. A couple of instances of "unable to Charge", , but able to just a few minutes later. This morning, all of a sudden, trying to shift to Reverse to back out of my garage, "Shift to Park". Will not let me move.
There are a number of YouTube videos on DIY fix for the shifter relay issue. One show bending the contact a bit, or replacing the relay, another has a guy cutting some wires!
I don't know where to find the build date.
Google "Chevy Volt where to find the build date?"
we need data sheet and application note on the L9367 chip.
Try searching the internet for "L9367 chip data sheet"?
Seems this is now a class action lawsuit. I was just told months to get a replacement part and several others on internet saying the same thing. no offer of a replacement car.
reports lately are that Gen 2 owners needing a BECM replacement are having them come in within a month. The class action? That will drag out for years.
1 - 7 of 139 Posts