Proactive Alerts, a feature of OnStar Advanced Diagnostics, are designed to help predict specific types of potential performance degradation based on current vehicle data. Several new Proactive Alerts have been added to select 2024 EV models that address 12V Battery Drain Detection. These new types of Proactive Alerts will help to identify parasitic drain or other issues related to the low voltage battery in electric vehicles. (Fig. 3)
Fig. 3
Proactive Alert Identifiers
The Proactive Alerts system collects and stores specific system performance data each Power-On cycle, which is transmitted via the cellular system (OnStar). The transmitted data is stored off-board the vehicle and analyzed by special algorithms to detect degraded performance. When monitored system performance degrades to predetermined levels, the off-board system sends a Proactive Alert Identifier. Currently, no associated DTCs are stored in the vehicle.
12V Battery Drain Detection uses available vehicle data to determine if an excessive amount of battery capacity, measured in amp-hours, was drawn from the 12V battery while the vehicle was in Off mode. The new Proactive Alerts are:
| Proactive Alert Identifier | Description |
| SAC006 | Slow Drain Detected on 12 V Battery |
| SAC007 | Reduced 12V Battery Charging due to High Voltage Battery Low State of Charge |
| SAC008 | Severe Drain Detected on 12V Battery |
| SAC009 | 12 V Battery Low State of Charge due to Possible Parasitic Drain |
The diagnostics for each Proactive Alert Identifier can be found in the Service Information under Engine/Propulsion > Starting, Charging, and Low Voltage Energy Storage > Diagnostic Information and Procedures. An example is shown below. (Fig. 4)
Fig. 4
Repair Procedures
When reviewing Service Information procedures, be sure to search for the specific Proactive Alert Identifier and not a generic term for the repair, such as “battery.” (Fig. 5)
Fig. 5
Follow the diagnostic and repair procedures for each Proactive Alert Identifier. As part of the Diagnostic System Check, check for related Service Bulletins, e.g., Vehicle Wide Programming Instructions.
Customer and Dealership Messages
Customers must sign up for the service through OnStar to receive Proactive Alerts. Once enrolled, they may receive Push Notifications and Mobile Inbox messages through the myBrand App (Fig. 6) when potential performance degradation is detected. Additional Notification channels, such as e-mail and text message, will be available in the future.
Fig. 6
For more information about the operation of 12V Battery Drain Detection, refer to the Service Information under Diagnostic Overview, Starting Point, and Programming > Vehicle Diagnostic Information > Description and Operation > Proactive Alerts Description and Operation (Document ID: 6535725).
– Thanks to Brett Holsworth
