Climatronic Refrigerant Shut-Off Valve (N422)/Coolant Shut-Off Valve (N82) Location, Control and Function
Climatronic Refrigerant Shut-Off Valve (N422)/Coolant Shut-Off Valve (N82) Location, Control and Function
• On certain vehicles (depending on the engine), vacuum-controlled coolant shut-off valves - A - were installed on vehicles without an "auxiliary heater" from start of production. Electrically controlled shut-off valves - B - were introduced later as a running change. These valves are referred to as a climatronic refrigerant shut-off valve (N422) or a coolant shut-off valve (N82) depending on the engine version and on the time of production. Refer to and the Vehicle Diagnostic Tester in "Guided Fault Finding" function.
• Pay attention to the flow direction of the coolant - arrow - when installing.
• This valve is referred to as a climatronic refrigerant shut-off valve (N422) or a coolant shut-off valve (N82) depending on the engine version and on the time of production. Refer to and the Vehicle Diagnostic Tester in "Guided Fault Finding" function.
• The activation of the Climatronic refrigerant shut-off valve / coolant shut-off valve depends on the version of the vehicle (either by the Climatronic control module (J255) or by the engine control module).
Information regarding a coolant shut-off valve activated by vacuum
The component location and version of the climatronic refrigerant shut-off valve - B - and of the coolant shut-off valve - A - depends on the engine, the version of the vehicle and on the production date.
• This illustration shows the allocation and version of the Climatronic refrigerant shut-off valve - B - with a 6 cylinder FSI engine as installed at the start of production. Version "1" Climatronic refrigerant shut-off valve - B - is installed near the cylinder head.
• The Climatronic refrigerant shut-off valve - B - is installed in the plenum chamber in certain vehicles (Audi Q5 with a 6-cylinder diesel engine). This illustration shows version "2" of the Climatronic refrigerant shut-off valve.
• The Climatronic refrigerant shut-off valve was installed only on vehicles with a 6 cylinder FSI engine at start of production. It was introduced on other engine as a running change in MY 2008. The exact introduction depends on the vehicle equipment level and the build date.
Make sure the vacuum hoses are attached correctly when installing the Climatronic refrigerant shut-off valve - B -.
• The vacuum hose to the shut-off valve - A - is attached to the connection "3" - C - on version "1" The vacuum supply from the engine comes from the connection "2" - D -.
• On version "2" the vacuum hose - C - to the shut-off valve - A - is connected to connection "3". The vacuum supply from the engine comes from the connection "2" - D -.
• The illustration shows the allocation on a MY 2009 4-cylinder diesel engine.
• The ventilation of the shut-off valve vacuum diaphragm - A -, for example, on version "2" of the Climatronic refrigerant shut-off valve - B - occurs via the connection "1" under the cap - E -.
• The vacuum hose - C - (leading to the shut-off valve - A -) is identified with a white mark, depending on the version.
• Pay close attention to the correct vacuum hose allocation on the Climatronic refrigerant shut-off valve - B -.
• If the vacuum hoses are interchanged, there may be no heating in the passenger compartment.
• The Climatronic control module (J255) display and control head checks the Climatronic refrigerant shut-off valve - B - for functionality in specific time intervals, for example, after every 20 engine starts. If the vacuum hoses are incorrectly connected to the Climatronic refrigerant shut-off valve - B -, then the coolant shut-off valve - A - is activated briefly. If the hoses are interchanged, the vacuum will remain in the vacuum hose vacuum diaphragm - A - for an undetermined amount of time after the activation is completed. The shut-off valve - A - will not open. Coolant will flow into the heater core and the A/C system will not heat when the shut-off valve - A - is closed.
• If the vacuum hoses are connected incorrectly, the engine will still take in some fresh air through the connection "1" on the Climatronic refrigerant shut-off valve. This can lead to additional problems in the engine idle RPM which will be entered in the engine control module data memory.
Information for all
• An electric shut-off valve - B - or a vacuum-controlled coolant shut-off valve - A - is installed either in the plenum chamber or in the engine compartment depending on the engine and the vehicle version.
• The Climatronic refrigerant shut-off valve / coolant shut-off valve can then be activated by the A/C controls (either directly or by the engine control module) when the A/C system is "OFF". The engine RPM must be lower than 5,000 and the coolant temperature must be below 90 °C (194 °F). Shutting off the coolant circuit to the A/C heater core accelerates the engine warming up when the coolant is cold.
• The Climatronic refrigerant shut-off valve can be switched off by the "adaptation" function in the A/C system. Refer to Vehicle Diagnostic Tester under "Guided Fault Finding".
• Depending on the version of the Climatronic control module (J255) , coolant pump (V50) may be referred to as water pump (V36) in Guided Fault Finding. Refer to the Vehicle Diagnostic Tester under "Guided Fault Finding".
• The coolant pump (water pump ) is controlled by the recirculation pump relay (J160) (via the same output as the climatronic refrigerant shut-off valve (N422) ) or, as a running change in MY 09, directly by the Climatronic control module. Activation takes place after the Climatronic control module makes the request via the engine control module on certain vehicles (Audi Q5 Hybrid). Pay attention to the correct version of the Climatronic control module (J255) and the correct coding and adaptation. Refer to the Vehicle Diagnostic Tester under "Guided Fault Finding".
• If the vehicle has a recirculation pump relay (J160) (for example, MY 08 vehicles), then the coolant recirculation pump (water pump) is always activated when the ignition is turned on, when the Climatronic refrigerant shut-off valve (N422) / coolant shut-off valve (N82) is not on (for example, when the temperature is set to "warm" on the Climatronic control module A/C control head). Refer to => [ Coolant Recirculation Pump (V50) (Water Pump (V36)) ] Coolant Recirculation Pump (V50) (Water Pump (V36)).
• With the ignition on and depending on the coolant temperature the setting on the Climatronic control module, the coolant recirculation pump (water pump ) is activated by a request from the Climatronic control module via the engine control module on certain vehicles (for example, Audi Q5 Hybrid) without a recirculation pump relay (J160) (running change from MY 09). Refer to => [ Coolant Recirculation Pump (V50) (Water Pump (V36)) ] Coolant Recirculation Pump (V50) (Water Pump (V36)).
• The coolant recirculation pump (water pump) Climatronic refrigerant shut-off valve activation depends on the vehicle equipment level and the vehicle date of manufacture. Refer to Vehicle Diagnostic Tester in "Guided Fault Finding" function.
• If the vehicle has a coolant recirculation pump (water pump ) and a Climatronic refrigerant shut-off valve / coolant shut-off valve that are activated directly by the Climatronic control module, then the Climatronic control module will store any faults on these components. Pay attention to the version, the coding and the adaptation on the Climatronic control module. Check using the Vehicle Diagnostic Tester under "Guided Fault Finding".
• The coolant recirculation pump (water pump) versions and activation differ depending on the version of the vehicle and production period. From MY 12 beginning with start of production, pumps that were controlled by a 500 Hertz signal (500 pulses per second) are being replaced by pumps that are controlled by a 100 Hertz signal depending on the engine. Pumps, controlled by a 100 Hertz signal, also have a diagnostic function and are controlled by the engine control module. Check for the correct allocation; refer to Vehicle Diagnostic Tester in "Guided Fault Finding" function, to the and to the Parts Catalog.