For those that disabled ERDTT using hardware hacks, or wish they could disable it without making any modifications, here is a neat solution. It uses an app called MyVoltHold and OBD2. I tested MyVoltHold app in real world conditions today to disable ERDTT, and it works like a charm!
https://play.google.com/store/apps/details?id=com.thunkable.android.myvoltapp.MyVoltHold&hl=en
The app was originally developed to provide Hold mode for 2012 and older Volts. The hidden benefit is that it can be used to disable ERDTT as well, in all Gen 1 Volts. My Volt is 2013. You pair the app to an ELM327 compatible OBD2 adapter (bluetooth or wifi), and then you can request the engine to turn OFF, from the app.
As per the developer, if you do not want the engine to run too long (ala AriC), you can connect to the OBD2 adapter before you start the car (OBD2 port can be activated by hitting Power Button without hitting brakes) and make the engine off request as soon as you start the car. Another option is to start the car while it is plugged in, make a request to stop the Engine, and then unplug. You need to leave the app running for as long as the car is on.
In summary, this app can
-> Enable Hold mode in 2011 and 2012 Volts
-> Disable ERDTT in all Gen 1 Volts
-> Allow Gen 1 Volt to use battery up to 16% SOC (useful if you want to avoid running gas engine when the battery goes to zero miles just as you are arriving at your home/destination).
PS: This is the OBD2 BT adapter I have been using for last few years. Always hooked to the car (except when I request OnStar to run a scan). Has worked without any issues so far: https://www.amazon.com/gp/product/B00PJPHEBO/
https://play.google.com/store/apps/details?id=com.thunkable.android.myvoltapp.MyVoltHold&hl=en
The app was originally developed to provide Hold mode for 2012 and older Volts. The hidden benefit is that it can be used to disable ERDTT as well, in all Gen 1 Volts. My Volt is 2013. You pair the app to an ELM327 compatible OBD2 adapter (bluetooth or wifi), and then you can request the engine to turn OFF, from the app.
As per the developer, if you do not want the engine to run too long (ala AriC), you can connect to the OBD2 adapter before you start the car (OBD2 port can be activated by hitting Power Button without hitting brakes) and make the engine off request as soon as you start the car. Another option is to start the car while it is plugged in, make a request to stop the Engine, and then unplug. You need to leave the app running for as long as the car is on.
In summary, this app can
-> Enable Hold mode in 2011 and 2012 Volts
-> Disable ERDTT in all Gen 1 Volts
-> Allow Gen 1 Volt to use battery up to 16% SOC (useful if you want to avoid running gas engine when the battery goes to zero miles just as you are arriving at your home/destination).
PS: This is the OBD2 BT adapter I have been using for last few years. Always hooked to the car (except when I request OnStar to run a scan). Has worked without any issues so far: https://www.amazon.com/gp/product/B00PJPHEBO/