what is rear ebs on a 97 grand prix?

Question

c1242 is the code it reads rear ebs does not hold motor

Answer 1

Are you sure you did not mean ABS? The (A)ntilock (B)rake (S)ystem does have a hold mode. The ABS code you are describing means that one of the Valve is sticking, or the motor is not working at all. Duding an ABS skid, the valve opens and closes (Hold) to prevent the tire from losing traction.

Answer 2

It means and I know you meant ABS thet one of the sensors on the rear brakes is bad or lost it's comunication with the exciter ring. Meaning it can't tell if the wheel is locking up or not when you hit your brakes so it can't keep that wheel or wheel from lockin up