Refrigerant Cut-Off Valve

Shut-Off Valve with Two Switching States (Open Or Closed)

• Hybrid Battery Refrigerant Shut-Off Valve 1 -N516- (for example the Audi Q5 Hybrid)
• Heater and A/C Unit Refrigerant Shut-Off Valve -N541- (for example on Audi A3 e-tron)
• High-Voltage Battery Heater Core Refrigerant Shut-Off Valve -N542- (for example on Audi A3 e-tron)
• Refrigerant Shut-Off Valve -V424- (for example on Audi Q7 e-tron)

• If the shut-off -A- is not activated by the electronics, it is open and lets the refrigerant flow through to the evaporator in the A/C unit.
  Fig 1: HYBRID BATTERY REFRIGERANT SHUT-OFF VALVE 1 -N516-

  Courtesy of AUDI OF AMERICA, LLC
• The shut-off valve -A- is installed on vehicles with the battery cooling module. It is activated in hybrid mode when no A/C system operation is desired for the passenger compartment or for the Hybrid Battery Unit -AX1-, but is necessary for battery cooling.
• Observe the arrow -B- attached to the shut-off valve -A-, which shows the flow direction of the refrigerant (from the condenser to the evaporator in the A/C unit)
• The solenoid coil -C- attached to the shut-off valve is activated for example from the Battery Regulation Control Module -J840- the appropriate Wiring Diagram. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding"  Function for the A/C System and the Battery Regulation.
• On a vehicle with two evaporators (one in the A/C unit and one for example on the Audi Q5 Hybrid) in the battery cooling module, if the measured temperature on one of the evaporators corresponds to the target value or the target value falls short, but does not reach the required target value on the other evaporator, the following adjustment is performed: the relevant control module (for example the Battery Regulation Control Module -J840- on the Audi Q5 hybrid) activates the electric A/C compressor with increased speed (thereby increasing the A/C cooling output and decreasing the pressure on the low pressure side as well as the evaporator temperature) via the A/C Compressor Control Module -J842-. If the target value falls short for the temperature of one of the evaporators, the relevant control module (for example the Battery Regulation Control Module -J840- on the Audi Q5 Hybrid the Hybrid Battery Refrigerant Shut-Off Valve 1 -N516- or the Hybrid Battery Refrigerant Shut-Off Valve 2 -N517-) activates so that the evaporator which is too cold is no longer supplied with refrigerant. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding"  Function for the A/C System and Air Conditioning (1 Of 3) / Air Conditioning (3 Of 3) (vehicle-specific Service Information). (for the specific vehicle).

Shut-Off Valve, which is Regulated via the Characteristic Curve

• Refrigerant Shut-Off Valve 2 -N640- through Refrigerant Shut-Off Valve 5 -N643- (for example on Audi Q7 e-tron)
• Refrigerant Expansion Valve 1 -N636- (for example on Audi Q7 e-tron)

• The shut-off valve -A- is activated via a step motor -B- from the respective control module via the characteristic curve (opened or closed).

  Courtesy of AUDI OF AMERICA, LLC

• If the shut-off valve works as a regulator valve (for example on the Audi Q7 as Refrigerant Expansion Valve 1 -N636-) it is only open until the temperature for the heat exchanger is reached. Refer to Air Conditioning (1 Of 3) / Air Conditioning (3 Of 3) (vehicle-specific Service Information).
• Shut-off valves activated via the step motor do not have a specified resting position. For this reason before performing procedures on the refrigerant circuit it must be set to a specified position (open or closed). Refer to Air Conditioning (1 Of 3) / Air Conditioning (3 Of 3) (vehicle-specific Service Information).
• Depending on the design of the refrigerant circuit multiple shut-off valves can be combined in one valve block (for example on the Audi Q7 e-tron). Refer to Air Conditioning (1 Of 3) / Air Conditioning (3 Of 3) (vehicle-specific Service Information).
• The step motor is adapted and activated via the data wires (LIN Bus) from the respective control module according to its component location. Refer to Air Conditioning (1 Of 3) / Air Conditioning (3 Of 3) (vehicle-specific Service Information). Use the Vehicle Diagnostic Tester in the "Guided Fault Finding"  function.