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2017 Premier with 46,000 miles. Out of the blue, the MIL light has come on. OnStar reports DTCs P0AEE, P0BD2, P0BDC are set. These codes persist after the proverbial 12 Volt battery negative terminal reset, and after 10 full on off cycles on the car. The latest recall software was installed on June 8th. Could this be just the calibration refered to in Service Bulletin 18-NA-064 needed? Other than the MIL light being lit, the car seems to be running just fine. I've never had a single problem until this.
 

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Discussion Starter · #3 ·
Buy a new 12v battery recent?
No, its the original 12V battery. But I checked the 12V battery voltage wile the negative terminal was lifted, and it was 13.9 volts. I assumed that meant it was probably OK.
 

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2017 Premier with 46,000 miles. Out of the blue, the MIL light has come on. OnStar reports DTCs P0AEE, P0BD2, P0BDC are set. These codes persist after the proverbial 12 Volt battery negative terminal reset, and after 10 full on off cycles on the car. The latest recall software was installed on June 8th. Could this be just the calibration refered to in Service Bulletin 18-NA-064 needed? Other than the MIL light being lit, the car seems to be running just fine. I've never had a single problem until this.
Stan,

Several weeks ago the Service Vehicle Soon Warning Light illuminated. 2017 LT, 38,250 miles. (The Chevy app says: No Issues. Good to Go)

The dealer did the scan and informed me that the hybrid positive contractor is stuck closed and will have to be replaced. The part has been ordered and should be available next week. Labor will take approximately five hours. It's covered under the recall warranty.
Although the MIL continues to be illuminated, the advisor said the car is safe to drive, but offered little insight or understanding of the issue.

Update: Several weeks later the part still has not arrived. I suspect it has something to do with the battery recall.

The service advisor continues to assure me that the car is safe.

I've attached the service reports so you can compare error codes.

Bernie




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Stan,

Several weeks ago the Service Vehicle Soon Warning Light illuminated. 2017 LT, 38,250 miles. (The Chevy app says: No Issues. Good to Go)

The dealer did the scan and informed me that the hybrid positive contractor is stuck closed and will have to be replaced. The part has been ordered and should be available next week. Labor will take approximately five hours. It's covered under the recall warranty.
Although the MIL continues to be illuminated, the advisor said the car is safe to drive, but offered little insight or understanding of the issue.

Update: Several weeks later the part still has not arrived. I suspect it has something to do with the battery recall.

The service advisor continues to assure me that the car is safe.

I've attached the service reports so you can compare error codes.

Bernie




Attachments
My 2017 has had the MIL on twice for this, it started after the Recall software update. I think it is highly unlikely that there is anything wrong with the contactor and that something in the software update is causing a false positive on this. If the contactor was really stuck then the negative one would also end up welded on and the high voltage wouldn't be able to be turned off to the inverter since the precharge circuit is on the positive side of the battery. The gist of all of this is that turning on (and especially off) ~400VDC is no trivial matter and the contactors have to be opened and closed with near zero current flowing or they will weld themselves on, this is the reason for the test and code. I'm guessing that something changed in the timing of when the voltages are sampled and now we are getting these codes triggered.
 

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2017 Premier with 46,000 miles. Out of the blue, the MIL light has come on. OnStar reports DTCs P0AEE, P0BD2, P0BDC are set. These codes persist after the proverbial 12 Volt battery negative terminal reset, and after 10 full on off cycles on the car. The latest recall software was installed on June 8th. Could this be just the calibration refered to in Service Bulletin 18-NA-064 needed? Other than the MIL light being lit, the car seems to be running just fine. I've never had a single problem until this.
I've not seen those codes, my search comes up with propulsion power reduced, if that happened I expect you'd notice. If you have access to an OBD2 scanner you could check for more codes as OnStar doesn't seem to even acknowledge many of them.
 

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My 2017 has had the MIL on twice for this, it started after the Recall software update. I think it is highly unlikely that there is anything wrong with the contactor and that something in the software update is causing a false positive on this. If the contactor was really stuck then the negative one would also end up welded on and the high voltage wouldn't be able to be turned off to the inverter since the precharge circuit is on the positive side of the battery. The gist of all of this is that turning on (and especially off) ~400VDC is no trivial matter and the contactors have to be opened and closed with near zero current flowing or they will weld themselves on, this is the reason for the test and code. I'm guessing that something changed in the timing of when the voltages are sampled and now we are getting these codes triggered.
Thanks for the quick and informative explanation.
I've owned my Bolt for 4 years and much about the electronics are still Greek to me.

Bernie
 

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here's another one of these errors after the latest update. not getting this update done till my new battery modules are ready...
 

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2017 Premier with 46,000 miles. Out of the blue, the MIL light has come on. OnStar reports DTCs P0AEE, P0BD2, P0BDC are set. These codes persist after the proverbial 12 Volt battery negative terminal reset, and after 10 full on off cycles on the car. The latest recall software was installed on June 8th. Could this be just the calibration refered to in Service Bulletin 18-NA-064 needed? Other than the MIL light being lit, the car seems to be running just fine. I've never had a single problem until this.
This is a follow up to my 20 APR post.
The MIL illuminated periodically during the passed 6 months.
The dealer finally replaced the High Voltage Battery Disconnect Relay today. It took 5 month for the part to be delivered
The entire battery had to be removed, a "smoke test" (whatever that is) performed, and a cooling system purge.
The time allotted was 5 hours.
Note in attached work order, the tech states: "To accommodate removal of battery...narrow lift opening requires lowering of battery on angle".

Bernie


Font Parallel Screenshot Document Paper
 

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For the benefit of anyone else coming across this thread - when you get weird codes being thrown by the car with no obvious reason the very first thing to do it to check the health of your 12V battery. The car depends on this battery while turned off and also to run diagnostics when you turn on the car before the main battery battery contactor is closed. If the 12V battery is weak, its voltage can sag under load, and this can trigger all sorts of weird sensor anomalies which are recorded by the car as errors.

It's not enough to just test the battery voltage, you have to put it under a load to make sure the voltage doesn't sag too much when the car is drawing power from it. Cheap but effective battery load testers are available from almost any auto parts store - it's money well spent if it saves you a trip to the dealer by identifying a bad battery which is easy to replace on your own.
 

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This is a follow up to my 20 APR post.
The MIL illuminated periodically during the passed 6 months.
The dealer finally replaced the High Voltage Battery Disconnect Relay today. It took 5 month for the part to be delivered
The entire battery had to be removed, a "smoke test" (whatever that is) performed, and a cooling system purge.
The time allotted was 5 hours.
Note in attached work order, the tech states: "To accommodate removal of battery...narrow lift opening requires lowering of battery on angle".

Bernie


View attachment 38221
My guess on the smoke test is that they used some type of smoke to verify the battery was properly sealed to prevent water from entering the battery.
 
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