Parts for your 2009 Nissan Serena-Tx valve

2009 Nissan Serena TX Valve (Thermal Expansion Valve)

Referencing technical sources: the 2009 Nissan Serena (C25) uses a thermal expansion valve (TXV) in its air-conditioning system. This is documented in the Nissan Serena C25 factory service manual (Heater & Air Conditioning/HA section) and reflected in Nissan’s FAST parts catalogue, which lists an expansion valve for the C25 evaporator assembly. DENSO A/C training material for Nissan applications also notes a TXV-controlled R134a system with a receiver-drier, not an orifice tube setup.

For the 2009 Serena, the TX valve’s job is to meter the right amount of refrigerant into the evaporator based on superheat at the outlet. That keeps cabin temps stable, stops the evaporator from icing up, and helps the compressor work efficiently—handy for Kiwi and Aussie stop–start traffic and warm summer runs.

The TXV sits at the evaporator inlet, inside the HVAC unit behind the glovebox/firewall area. It senses outlet temperature via a capillary bulb and adjusts flow through a needle and seat. When it sticks or drifts out of spec, the Serena can blow warm at idle, cycle between too cold and not cold, or show frosty lines at the firewall. A set of gauges will often reveal low suction with high superheat (underfeeding) or low superheat with frosting (overfeeding).

It’s not a routine replacement item, but it’s smart to check TXV performance during A/C servicing if there are cooling complaints, contamination, or pressure readings that don’t stack up. If the compressor has failed, has shed debris, or there’s acid formation, technicians commonly replace the TXV and the receiver–drier (often integrated with the condenser) and flush the lines. Always fit new O‑rings, lubricate with the correct PAG oil, evacuate thoroughly, and recharge to the label spec under the bonnet. The Serena runs R134a, confirm the exact charge and oil spec from service data.

Replacement needs refrigerant recovery and proper re-gas, so it’s a licensed tech job. On install, the sensing bulb must be correctly positioned and re-insulated—missing insulation can throw superheat control out and cause inconsistent cooling. The valve isn’t adjustable and doesn’t need periodic tweaking, clean, correct installation and system cleanliness are what keep it happy.

• Tell-tales of a crook TXV: uneven vent temps, evaporator icing, noisy hissing at the dash, abnormal high/low side pressures.
• Best practice with a major A/C repair: TXV + drier replacement, system flush, new O‑rings, vacuum, and charge to spec.

Popular questions about 2009 Nissan Serena TX valve

Where is the TX valve on a 2009 Serena?
The TXV is mounted at the evaporator inlet inside the HVAC case, typically accessed from behind the glovebox area. The refrigerant lines pass through the firewall into this unit. While the glovebox and trims can come out fairly quickly, the valve swap still requires recovery, vacuum, and recharge gear.

Do I need to replace the TX valve when changing the compressor?
Often recommended if the old compressor failed mechanically or there’s contamination, because debris can lodge in the TXV and mess with metering. At minimum, replace the receiver–drier and flush the system. Many workshops bundle a TXV with compressor and condenser/drier to protect the warranty and avoid repeat jobs.

What refrigerant and oil does it use?
The 2009 Serena uses R134a. The charge amount and oil type are on the under‑bonnet label and in Nissan service data, use the specified PAG oil grade and quantity. Sticking to the correct amounts helps the TXV regulate superheat properly and keeps the system cooling like it should.