GM Repair Problems? Ask GM Repair Expert Now.
Hello and welcome!
Do you have access to a scan tool to retrieve fault codes from the vehicle?
Two mode hybrid systems does not use a conventional starter that is powered by the 12v battery. The electronic motors inside the transmission is what starts the vehicle, the 300 volt battery cranks the engine.
A "Jump Assist" procedure is available, but must use a capable scan tool to place the system into Jump Assist mode.Also, the hybrid battery must be above 194 V to initiate Jump Assist.Anytime a battery charger or booster pack is connected to the 12 V battery, the ignition key should always be in the OFF position.
A service hybrid system message indicates a fault code in the hybrid 300v system causing the vehicle not to start.
I am so sorry to hear that, was the key left on and the 12v battery died?
Did you leave the battery on a charger or just tried to jump start?
You have only one option to try and reset the system.
1. Ignition key OFF, disconnect the 12 V battery negative cable and positive cable.
2. Wait 10 minutes.
3. Hold the cables together for 2 minutes, or use a jumper wire.
4. Reconnect the 12 V battery cables.
Please be aware, that by doing this procedure it has a chance activate the back up battery in the On Star system. the battery will need to be replaced to clear the codes and the red light on the mirror.