Probing a vehicle's AC system with a manifold gauge set, you find a low-side pressure of 10 psi and a high-side pressure of 100 psi (ambient temperature is 32 degrees C). What do these readings indicate?

1. The system has too much refrigerant
2. The system has low refrigerant charge (typical of a leak)
3. The compressor is failing internally
4. The expansion valve is stuck open