Parts for your 2004 Mitsubishi Pajero-Tx valve

2004 Mitsubishi Pajero TX-Valve: What It Does and When to Service It

Yes, the 2004 Mitsubishi Pajero uses a TX-valve (thermal expansion valve) in its factory DENSO air-conditioning system. This is confirmed by Mitsubishi’s workshop documentation for Group 55 (Heating, Ventilation & Air Conditioning) and Mitsubishi ASA parts catalogue listings that identify an “expansion valve” for NM/NP-series Pajero models. On vehicles fitted with rear air (common on higher trims), there’s a second TX-valve at the rear evaporator as well.

The TX-valve meters the flow of refrigerant into the evaporator, matching it to heat load so the system cools efficiently without icing. By sensing evaporator outlet temperature/pressure, it opens and closes to maintain optimal superheat. When it sticks or drifts out of spec, the Pajero’s A/C can blow warm at idle, cycle erratically, or show frosting on lines. Left alone, this can strain the compressor and bump up fuel use.

As part of sensible servicing, a Pajero’s TX-valve doesn’t need routine replacement on a time basis, but it should be assessed any time the dash is out, the evaporator is being inspected, or the system performance is off. If the system has been contaminated by moisture or debris (for example after a compressor failure), replacing the TX-valve is good practice along with the receiver–drier/desiccant.

• Only a licensed A/C technician should discharge and recharge the R134a system under AU/NZ regs.
• If the system is opened, renew the receiver–drier and all disturbed O-rings, use the correct PAG oil, and vacuum the system thoroughly before charging by weight to the factory spec.
• Front-only A/C has one TX-valve at the front evaporator, dual A/C adds a second at the rear unit in the left rear quarter. Diagnose both if cooling imbalance exists.
• Look for tell-tales: fluctuating vent temps, high low-side pressure readings or deep vacuum at the low side, and frost at the evaporator inlet can all point to a faulty valve.

For owners chasing reliable cold air on hot Aussie or Kiwi days, a healthy TX-valve is a quiet hero. If the Pajero cools poorly, hunts, or ices up, having an expert pressure-test, check superheat behaviour, and evaluate the TX-valve is the smart next step.

Popular questions about 2004 Mitsubishi Pajero TX-valve

Where is the TX-valve on a 2004 Pajero?
On front A/C systems it’s mounted at the front evaporator, typically behind the dash on the passenger side, attached to the evaporator inlet/outlet pipes. Pajeros with rear air have a second TX-valve at the rear evaporator inside the left rear quarter area. Access usually requires trim or dash removal.

Do TX-valves need regular replacement?
Not on a time or kilometre basis. They’re replaced when faulty or when the system’s been contaminated (e.g., after a compressor failure). If the A/C is opened up for major work, many technicians recommend renewing the TX-valve and receiver–drier as preventative maintenance.

What symptoms suggest a bad TX-valve on a Pajero?
Common signs include warm air at idle but cooler at speed, vent temperatures that swing hot–cold, visible frosting on the evaporator inlet line, or pressure readings that are abnormally high or very low on the low side. Proper diagnosis with gauges and temperature probes is essential before replacement.