Air conditioning circuit for a motor vehicle, through which there circulates a refrigerant and which comprises, in the direction in which the refrigerant circulates: ∘ a compressor , ∘ a first heat exchanger intended to have passing through it a flow of air external to the motor vehicle and positioned downstream of the compressor , ∘ an ejector positioned downstream of the first heat exchanger and comprising: • a first refrigerant inlet , connected to said first heat exchanger , • a second refrigerant inlet , and • a refrigerant outlet , ∘ a refrigerant phase-separation device comprising: • a refrigerant inlet connected to the refrigerant outlet of the ejector , • a first refrigerant outlet for refrigerant in the gaseous phase, which is connected to the compressor , and • a second refrigerant outlet for refrigerant in the liquid phase, ∘ an expansion device positioned downstream of the second refrigerant outlet of the phase-separation device , ∘ a second heat exchanger intended to have passing through it a flow of internal air intended for the motor vehicle interior, said second exchanger being positioned downstream of the expansion device , between said expansion device and the second refrigerant inlet of the ejector , characterized in that the air conditioning circuit further comprises a bypass line (A) bypassing the phase-separation device and connecting: ∘ a first junction point positioned downstream of the refrigerant outlet of the ejector , between said ejector and the phase-separation device , and ∘ a second junction point positioned downstream of the first outlet of the phase-separation device , between said phase-separation device and the compressor , said bypass line (A) comprising a third heat exchanger . ∘ a compressor , ∘ a first heat exchanger intended to have passing through it a flow of air external to the motor vehicle and positioned downstream of the compressor , ∘ an ejector positioned downstream of the first heat exchanger and comprising: • a first refrigerant inlet , connected to said first heat exchanger , • a second refrigerant inlet , and • a refrigerant outlet , • a first refrigerant inlet , connected to said first heat exchanger , • a second refrigerant inlet , and • a refrigerant outlet , ∘ a refrigerant phase-separation device comprising: • a refrigerant inlet connected to the refrigerant outlet of the ejector , • a first refrigerant outlet for refrigerant in the gaseous phase, which is connected to the compressor , and • a second refrigerant outlet for refrigerant in the liquid phase, • a refrigerant inlet connected to the refrigerant outlet of the ejector , • a first refrigerant outlet for refrigerant in the gaseous phase, which is connected to the compressor , and • a second refrigerant outlet for refrigerant in the liquid phase, ∘ an expansion device positioned downstream of the second refrigerant outlet of the phase-separation device , ∘ a second heat exchanger intended to have passing through it a flow of internal air intended for the motor vehicle interior, said second exchanger being positioned downstream of the expansion device , between said expansion device and the second refrigerant inlet of the ejector , ∘ a first junction point positioned downstream of the refrigerant outlet of the ejector , between said ejector and the phase-separation device , and ∘ a second junction point positioned downstream of the first outlet of the phase-separation device , between said phase-separation device and the compressor , said bypass line (A) comprising a third heat exchanger . <EOS>