edit: I re-read you post, and saw that you were able to drive after a jump start. How long did you leave the car "running" after the jump start? Was it long enough to charge up the 12V battery? I suspect your 12V battery is very low and possibly bad. Try to jump start again. Good chance you need a 12V battery.
Is the check engine light on?
other possibilities - my original reply:
here are some things to try:
From an old post, so may not apply to your Gen2, GM customer care rep speculating a car needed a "soft reset":
"Based on your description, rather than being "stuck in Service Mode" perhaps your vehicle required a soft reset for an unknown reason. If you are in this "no Ready light" situation, a soft reset is done by pressing the power button one time with your foot off the brake pedal to power down the vehicle. Open and close the driver's door, then wait until the overhead dome light extinguishes. Then start normally. "
Another possibility is it is stuck in service mode:
1) Power off your Volt by holding down the power button for 5 seconds w/o stepping on the brake pedal. (Remember to put your vehicle in Park first, which I naturally forgot because I was stressed out in traffic. It won't power down otherwise.)
2) Open your driver side door. Just a crack is fine. Leave it open for over a minute.
3) Close the door and power up like normal."
Otherwise, try unhooking the 12V battery and let it sit for several minutes, then hook it backup. It is possible your 12V battery is degraded and is causing these issues as well. Try leaving a jump pack or booster cables attached for a long while and get the 12V battery charged up a bit.
Is the check engine light on?
other possibilities - my original reply:
here are some things to try:
From an old post, so may not apply to your Gen2, GM customer care rep speculating a car needed a "soft reset":
"Based on your description, rather than being "stuck in Service Mode" perhaps your vehicle required a soft reset for an unknown reason. If you are in this "no Ready light" situation, a soft reset is done by pressing the power button one time with your foot off the brake pedal to power down the vehicle. Open and close the driver's door, then wait until the overhead dome light extinguishes. Then start normally. "
Another possibility is it is stuck in service mode:
Oh, right. A bit of a song and dance:
1) Power off your Volt by holding down the power button for 5 seconds w/o stepping on the brake pedal. (Remember to put your vehicle in Park first, which I naturally forgot because I was stressed out in traffic. It won't power down otherwise.)
2) Open your driver side door. Just a crack is fine. Leave it open for over a minute.
3) Close the door and power up like normal."
Otherwise, try unhooking the 12V battery and let it sit for several minutes, then hook it backup. It is possible your 12V battery is degraded and is causing these issues as well. Try leaving a jump pack or booster cables attached for a long while and get the 12V battery charged up a bit.
