AC Expansion Valve (TXV)

Replace the AC expansion valve (TXV) on the 2025 Rivian EDV 500, requiring evacuation and recharge of the refrigerant system.

Warnings

Tools required

Parts

• AC expansion valve (TXV) × 1 — Use OEM specification
• AC line O-rings × 1 — Use OEM specification
• R-1234yf refrigerant × 1 — Per vehicle specifications
• PAG oil (electric compressor compatible) × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and apply parking brake
2. Power down vehicle completely using touchscreen power-off procedure
3. Open hood and disconnect 12V auxiliary battery (located in front storage compartment)
4. Wait minimum 5 minutes for high-voltage system capacitors to discharge
5. Allow AC system to reach ambient temperature if recently operated
6. Verify refrigerant type is R-1234yf using identifier tool
7. Place fender covers to protect painted surfaces
8. Document current AC system performance concerns if any

Procedure

1. 1

   Recover refrigerant from AC system
   Connect R-1234yf recovery machine to both high and low side service ports. Follow machine instructions to completely recover all refrigerant from the system. Record the amount recovered for comparison during recharge. Ensure recovery is complete before disconnecting equipment.
2. 2

   Remove front underbody panel
   Remove fasteners securing the front underbody aerodynamic panel. This panel provides access to the AC components mounted in the front climate control module area. Store fasteners in organized manner for reinstallation.
3. 3

   Access HVAC module area
   Remove necessary trim panels and brackets to access the HVAC module on the passenger side of the vehicle. The TXV is located at the evaporator inlet on the HVAC case. May require partial removal of insulation blankets or heat shields in the area.
4. 4

   Disconnect TXV electrical connector
   Locate the electrical connector on the TXV sensor bulb. Press release tab and carefully disconnect the connector. Inspect connector pins for corrosion or damage. Mark connector orientation if needed for proper reinstallation.
5. 5

   Disconnect refrigerant lines from TXV
   Using appropriate refrigerant line disconnect tools, separate the liquid line connection at the TXV inlet and the evaporator connection at the TXV outlet. Cap all open connections immediately to prevent moisture and debris entry. Inspect fittings for damage or contamination.
6. 6

   Remove TXV mounting hardware
   Remove the bolts or clips securing the TXV to the evaporator housing. Carefully extract the TXV assembly, noting the orientation and position of the sensing bulb. Check for any additional mounting brackets that may secure the bulb to the evaporator outlet.
7. 7

   Install new TXV assembly
   Position new TXV in the same orientation as the original. Ensure sensing bulb makes proper contact with evaporator outlet line and is positioned correctly. Install mounting hardware and secure TXV to housing. Verify sensing bulb thermal contact is maintained.
8. 8

   Install new O-rings and reconnect refrigerant lines
   Lubricate new O-rings with appropriate refrigerant oil. Install O-rings on both refrigerant line connections. Reconnect liquid line to TXV inlet and evaporator line to TXV outlet. Ensure connections are fully seated and locked into place. Verify visual and tactile engagement.
9. 9

   Reconnect TXV electrical connector
   Clean connector if necessary and reconnect TXV sensor electrical connector. Ensure connector locks fully into place with audible click. Verify connector seal is properly seated to prevent moisture intrusion.
10. 10

    Evacuate AC system
    Connect evacuation equipment to service ports. Evacuate system to at least 500 microns vacuum. Maintain vacuum for minimum 30 minutes. System should hold vacuum without rising more than 200 microns, indicating no leaks. If vacuum does not hold, locate and repair leak before proceeding.
11. 11

    Recharge AC system
    Using digital scale and R-1234yf machine, charge system with manufacturer-specified amount of refrigerant (refer to underhood label for exact specification). Add appropriate amount of PAG oil if required to compensate for oil lost during recovery. Do not overcharge system.
12. 12

    Reinstall underbody panels and components
    Reinstall HVAC area insulation, brackets, and trim panels removed during disassembly. Install front underbody aerodynamic panel with all fasteners properly torqued. Ensure all clips and fasteners are secure.
13. 13

    Reconnect 12V battery
    Reconnect 12V auxiliary battery in front storage compartment. Ensure connection is clean and tight. Power up vehicle and allow systems to initialize.

Reassembly

1. Verify all electrical connectors are properly seated and locked
2. Ensure all refrigerant line connections are secure and fully engaged
3. Confirm all panels and underbody shields are reinstalled with proper fasteners
4. Check that no tools or parts were left in engine compartment or underbody area

Verification

• Start vehicle and activate climate control system in maximum cooling mode
• Monitor system pressures on AC machine gauges: low side should be 25-40 psi, high side 180-250 psi at idle with ambient temperature 70-80°F
• Verify temperature drop across evaporator is 30-40°F using temperature probes at cabin vents
• Listen for unusual noises from AC compressor or expansion valve operation
• Check all refrigerant connections with electronic leak detector or UV dye inspection
• Verify TXV is regulating properly by observing stable low-side pressure during operation
• Test AC performance in both driver and passenger zones at various temperature settings
• Scan for any HVAC-related diagnostic trouble codes using Rivian diagnostic software
• Verify system operates through multiple cooling cycles without pressure abnormalities
• Road test vehicle to confirm AC performance under various operating conditions

More procedures for this vehicle