Method and system to prevent vehicle driveaway during battery charging

1. A method to prevent vehicle movement when an onboard battery is being charged, comprising:

engaging a pawl with a parking gear wheel coupled to a driveline of the vehicle when an external power supply cord is plugged into a battery charging receptacle of the vehicle.

2. The method of claim 1 wherein:

the pawl is coupled to a gear shift selector;

the gear shift selector has a park position in which the pawl is engaged with the parking gear wheel; and

wherein the method further comprises preventing disengagement of the pawl by preventing the gear shift selector from moving out of the park position.

3. The method of claim 1 wherein the receptacle comprises a plug detector switch providing an indication of whether a plug is coupled to the receptacle; and wherein the method further comprises preventing a gear shift selector from being released based on a signal from the plug detector switch.

4. The method of claim 3 wherein the plug detector switch comprises a pin switch, which is depressed when a plug end of the external power supply cord is coupled with the receptacle.

5. The method of claim 1 , further comprising preventing a gear shift selector from being released when current is being supplied to the battery from the receptacle.

6. The method of claim 1 , further comprising preventing a gear shift selector from being released when a voltage source is coupled to the receptacle.

7. The method of claim 1 , wherein the vehicle further comprises:

an electric motor;

a transmission coupled to the electric motor; and

an internal combustion engine coupled to the transmission;

the method further comprising:

disabling the electric motor and the internal combustion engine while the external power supply cord is plugged into the receptacle.

8. A vehicle having a traction motor coupled to a battery, comprising:

a receptacle coupled to the battery and adapted to couple with a plug of an external power supply cord to charge the battery;

a parking gear wheel; and

a pawl adapted to engage with the parking gear wheel to prevent rotation of the parking gear wheel when a plug is coupled with the receptacle or an access door proximate the receptacle is open.

9. A vehicle system, comprising:

a traction motor coupled to a battery;

a parking gear wheel;

a pawl that selectively engages the parking gear wheel during charging of the battery by an external power supply;

an operator-actuated gear shift selector coupled to the pawl; and

a solenoid proximate the gear shift selector and adapted to lock the gear shift selector in place during charging of the battery by the external power supply.

10. A method to prevent a battery-powered vehicle from moving when the battery is being charged by an external power source, the vehicle having a battery, a battery charger coupled to the battery and to a receptacle, a pawl adapted to be engaged with a parking gear wheel coupled to a driveline of the vehicle, and a gear shift selector coupled to the pawl, the gear shift selector having a park position in which the pawl is engaged with the parking gear wheel, the method comprising:

detecting a vehicle condition indicating that an external power supply cord is plugged into the receptacle;

detecting whether a brake pedal coupled to the vehicle is being actuated;

detecting whether an ignition key switch coupled to the vehicle is actuated;

preventing the gear shift selector from moving out of the park position when any one of: the vehicle condition is detected, the brake pedal is unactuated, and the ignition key switch is unactuated.

11. The method of claim 10 wherein detecting a vehicle condition comprises one of:

detecting a voltage supply source coupled with the receptacle;

detecting a current flow to the battery charger from an external source;

determining that a plug is coupled to the receptacle by a plug detector; and

determining that an access door proximate the receptacle is open.