Parts for your 2019 Nissan Pathfinder-Tx valve

2019 Nissan Pathfinder TX valve: is it fitted, what it does, and when to replace it

Yes, the 2019 Nissan Pathfinder (R52) uses a TX valve (thermal expansion valve) in its air-conditioning system. This isn’t guesswork—technical references confirm it:

• Nissan Factory Service Manual (2019 Pathfinder R52, HA – Heating & Air Conditioning) lists the Expansion Valve and outlines removal/installation at the evaporator.
• Nissan Electronic Parts Catalogue (FAST) and dealer parts listings include an A/C Expansion Valve specifically for 2017–2019 Pathfinder R52.
• Aftermarket application catalogues (e.g., DENSO and Four Seasons) list a direct-fit TXV for 2017–2020 Pathfinder models.

On this model, the TX valve is a block-type metering device at the evaporator, regulating how much refrigerant flows in based on evaporator temperature and pressure. By controlling superheat, it helps the cabin cool quickly without icing the core, and it protects the compressor from liquid slugging. When the TX valve is healthy, vent temps stay nice and stable—especially on hot, humid days. If it sticks or clogs, drivers may notice weak cooling at idle, frosty or sweating lines near the firewall/evaporator, short-cycling, or temps that swing from too cold to lukewarm.

During regular servicing, the TX valve itself isn’t a routine replacement item, but it should be considered whenever the A/C system is opened for major work, there’s contamination (desiccant or debris), or there are recurring performance issues after leaks are fixed and the charge is set correctly. Good practice when replacing the valve includes:

• Recover refrigerant legally and safely, recharge with the refrigerant specified on the under-bonnet label (markets may use R-134a or R-1234yf).
• Replace the O-rings and lightly oil them with the correct PAG oil, add only the oil amount required for component change-out.
• Pressure test with dry nitrogen, then evacuate to a deep vacuum before recharging by weight to spec.
• If the system was contaminated or left open, replace the receiver/drier or condenser-integrated desiccant bag as specified in the service manual.

Access to the Pathfinder’s TX valve is at the evaporator connections, depending on workshop approach, it may involve under-dash/glovebox area work and tight clearances at the bulkhead. It’s a tidy job for an A/C technician with the right gear. Getting the charge spot-on after refit is key—too much or too little refrigerant can mimic a dodgy valve, so accurate weighing and proper diagnostics save a lot of back-and-forth.

Popular questions about the 2019 Nissan Pathfinder TX valve

Does the 2019 Pathfinder use a TX valve or an orifice tube?
It uses a TX valve. Nissan’s service documentation for the R52 platform specifies an expansion valve at the evaporator rather than a fixed orifice tube. This setup gives better control of superheat and more consistent cabin temps across varying conditions.

What are common signs the TX valve is failing?
Expect weak cooling at idle, vent temperatures that fluctuate, short compressor cycles, or visible frosting/sweating on the lines near the evaporator connection. Always rule out incorrect refrigerant charge, condenser airflow issues, and blend door faults before condemning the valve.

Can a TX valve be cleaned, or should it be replaced?
If debris or desiccant contamination has reached the valve, replacement is the reliable fix. Cleaning rarely restores proper metering for long. When replacing, address the root cause—flush as appropriate, renew O-rings, and replace the drier/desiccant bag if the system has been open or contaminated.