What does the code 0013 mean?

Judy you did not tell us what the letter in front of that is. The only thing I could find in the GM trouble codes is a B0013 Passenger Frontal Deployment Loop Stage 2 Open. This is usually due to an airbag deployment. It's the code for the front right circuit. May be it is possible that the passenger side airbag deployed and the bag and module were replaced, but the module circuit wasn't replaced. When the module senses the need to deploy, it sends a signal to the ring opening the line for the current to flow and causes the bag to deploy. Right now the circuit stays open, and causes this code. Possible that, until the circuit is replaced, the SRS system in inoperable and may be this is what makes your vehicle inoperable. Other causes could also be

• A short between the IPM high and low circuits

• An open or a high resistance in the IPM high or low circuits

• A short to ground or a short to voltage in the IPM high or low circuits

• The IPM connector

• The SDM connector

• A malfunctioning IPM

• A malfunctioning SDM

Where IPM is the dash air bag for the passengers side, and SDM is the air bag main module. Of course, all of this will be false if the code is not B0013.