[danieljlz]

Leave the car unplugged for 2 weeks and found the 12V battery dead. The high voltage battery still has 90% charge.
Charged the 12V battery up with an external charger.
The engine light is on when turn on the car. Using an ODBII tool and the codes are:
B2AAA - body
P1F64 - Powertrain
U3018 - Network
P0AC4 - Powertrain
P25C9 - Powertrain
P26AD - Powertrain
P1682 - Powertrain
P16A7 - Powertrain

Drive the car for 10km and the light is still on.
Turn the car off and turn it back on, the engine light is off.
Now the car drives as normal.

Using the ODBII tool and find all those fault codes are still there.

Since the engine light is off now, should I just clear up the faults codes or have the dealer to check the car?
Thanks for any suggestions.

 

[TSquare]

If they are not recurring, they will eventually go away on their own.
You may have a weak 12 volt battery though. It should not have discharged in only 2 weeks.

 

[El Dobro]

Have the battery tested at the dealer, it's covered under B2B.

 

[drmx]

Check the myChevrolet app and/or with your dealer for an applicable recall. I took mine in this week for this one:

https://gm.oemdtc.com/7895/16185-cu...art-or-loss-of-propulsion-2017-chevrolet-volt

Condition On certain 2017 model year Chevrolet Volt vehicles, the high voltage interlock connector behind the high voltage battery disconnect relay fuse block cover may be susceptible to becoming recessed back into the high voltage battery disconnect relay assembly. This may cause an electrical disconnect which could result in a loss of vehicle propulsion and/or a no start condition. The malfunction indicator lamp may be illuminated and DTC P0A0C – “high voltage system inter-lock circuit low” may be set. A “Shift To Park” message may also be displayed. Additionally, a subset of these vehicles may have a condition in which the 15A fuse in the high voltage battery disconnect relay may prematurely open. The open fuse may prevent the low voltage battery from being charged by the 14v DC power module. If this were to occur, the vehicle will provide warning to the driver and eventually lose electrical power. Once power is drained from the 12 volt battery, the vehicle may lose propulsion and will not start.

Correction Reprogram the hybrid powertrain control module 2; and if applicable, replace the 15 amp high voltage battery disconnect relay fuse.