Parts for your 2009 Holden Colorado-Tx valve

2009 Holden Colorado TX valve: what it does, where it lives, and how to look after it

Based on technical sources, the 2009 Holden Colorado (RC series) does use a thermostatic expansion valve (TX valve) in its air-conditioning system. The Holden/Isuzu workshop manual for the RC Colorado/D‑Max (2008–2012) HVAC section details an evaporator-mounted TX valve and outlines removal/refit at the heater/evaporator case. GM/ACDelco parts catalogues for RC Colorado list an “A/C Expansion (TX) Valve” as a service part, and the GM Service Information HVAC theory notes for these models describe a variable metering device at the evaporator inlet rather than a fixed orifice tube. All of that confirms the TX valve is fitted and relevant on 2009 Colorado models sold in Australia and New Zealand.

On a 2009 Colorado, the TX valve meters refrigerant into the evaporator, matching flow to heat load so the evaporator stays cold without icing. It reacts to temperature and pressure at the evaporator outlet, holding a steady superheat. That keeps cabin temps comfortable, protects the compressor, and helps fuel economy by avoiding overwork. The valve sits at the evaporator inlet on the passenger side of the dash/firewall area, where the two A/C lines pass through.

Tell‑tale signs the TX valve’s unhappy include:

• Warm air at idle but cooler when driving, or the opposite.
• Icing on the evaporator or suction line, or a frosty smell from the vents.
• Hissing/whistling near the dash and unstable vent temps.
• Odd gauge readings (very high or hunting high‑side pressure, or pressures equalising too quickly after shutdown).

If replacement’s on the cards, a licensed ARCtick technician must handle the refrigerant. Typical best practice is to recover the gas, remove the glovebox/trim to access the HVAC case, disconnect the lines at the firewall, and swap the TX valve with new O‑rings lubricated with the correct PAG oil. Always replace the receiver‑drier when the system’s opened, pull a deep vacuum to boil off moisture, and recharge to the quantity on the under‑bonnet label using R134a. A nitrogen or forming‑gas pressure test and an electronic leak check are well worth it before recharging.

As part of routine servicing, keep the condenser clean, ensure the evaporator drain is clear, check belt condition/tension, and run the A/C regularly to circulate oil. If the system’s been contaminated (black death, desiccant burst, or compressor failure), the TX valve can clog—flushing lines, replacing the drier, and fitting a new TX valve together is the smart move. Done right, the Colorado’s A/C will blow cold even on a scorcher.

Where is the TX valve on a 2009 Holden Colorado?

It’s mounted at the evaporator inlet inside the HVAC case, on the passenger side behind the dash. You’ll see the two A/C hard lines passing through the firewall—those connect directly to the TX valve. Access is via the glovebox area and HVAC covers.

What symptoms point to a bad TX valve on a Colorado RC?

Flaky cooling (cold then warm), icing on the suction line, hissing at the dash, and strange pressure readings are common. A stuck‑closed valve starves the evaporator, stuck‑open floods it and can cause icing and poor cooling.

Should the receiver‑drier be replaced when changing the TX valve?

Yes. Any time the system’s opened, the drier should be renewed to capture moisture and debris. Skipping it risks moisture freeze‑up, acid formation, and repeat faults—false economy on these systems.