AC High Pressure Switch

This procedure guides you through replacing the AC high pressure switch on a 2022 Rivian EDV 500, including safely discharging the AC system, accessing the switch in the electric vehicle's HVAC system, and recharging the system.

Warnings

Tools required

Parts

• AC high pressure switch × 1 — Use OEM Rivian specification
• O-rings for high pressure switch × 1 — Use OEM specification
• AC refrigerant × 1 — R-1234yf or per vehicle specification
• PAG oil for AC system × 1 — Use OEM specification

Preparation

1. Park vehicle on a level surface and engage parking brake
2. Ensure vehicle is powered off and key fob is at least 15 feet away from the vehicle
3. Using Rivian service mode procedures, disable the high voltage system and verify deactivation with appropriate voltage testing
4. Disconnect the 12V auxiliary battery negative terminal and wait 5 minutes for system capacitors to discharge
5. Verify AC system type and refrigerant specification (typically R-1234yf for 2022 EDV 500)
6. Locate the AC high pressure switch on the liquid line near the condenser in the front compartment
7. Document refrigerant capacity and PAG oil specifications from the vehicle label in the front compartment

Procedure

1. 1

   Access front compartment and locate AC components
   Open the front trunk (frunk) of the Rivian EDV 500. Remove the upper panel covering the HVAC components by releasing the fasteners along the perimeter. The AC high pressure switch is located on the high pressure liquid line between the condenser and the expansion valve, typically on the passenger side of the front compartment.
2. 2

   Disconnect electrical connector from high pressure switch
   Locate the electrical connector on the AC high pressure switch. Press the locking tab and carefully disconnect the electrical connector. Inspect the connector for corrosion or damage. If equipped with a secondary lock, remove it first.
3. 3

   Connect AC recovery machine
   Connect the AC manifold gauge set to the service ports on the vehicle. Attach the recovery machine following manufacturer instructions. Ensure all connections are secure and the recovery tank has sufficient capacity for the system charge (typically 1.5-2.0 lbs for this system).
   ⚠️Verify recovery machine is rated for R-1234yf refrigerant. Using incorrect equipment can cause contamination or equipment failure.
4. 4

   Recover AC refrigerant
   Following the recovery machine manufacturer's instructions, recover all refrigerant from the AC system. The machine will indicate when recovery is complete, typically showing vacuum or zero pressure. Record the amount of refrigerant and oil recovered for reference during recharging. Allow the system to stabilize for 5 minutes after recovery completes.
5. 5

   Remove high pressure switch
   Using the appropriate wrench or socket, carefully unscrew the AC high pressure switch from the liquid line fitting. Be prepared for residual refrigerant or oil to escape. Remove the switch completely and inspect the mounting port and threads for damage or debris. Keep the port capped or covered to prevent contamination.
6. 6

   Inspect and prepare new switch
   Compare the new AC high pressure switch with the old unit to verify correct part. Inspect the new O-rings and ensure they are properly seated in the grooves on the new switch. Apply a small amount of clean PAG oil to the O-rings to aid installation and prevent damage during threading.
7. 7

   Install new high pressure switch
   Thread the new AC high pressure switch into the liquid line fitting by hand, ensuring it starts correctly and does not cross-thread. Once hand-tight, use a torque wrench to tighten to the specified torque. Since no specific torque value is provided in the database, tighten to manufacturer specification found in Rivian service documentation (typically 8-12 ft-lbs for AC switches, but verify with OEM data).
8. 8

   Reconnect electrical connector
   Reconnect the electrical connector to the new AC high pressure switch, ensuring it clicks into place securely. Install any secondary locking mechanism if equipped. Gently tug on the connector to verify it is locked.
9. 9

   Evacuate AC system
   Connect the vacuum pump to the AC manifold gauge set. Open the appropriate valves and evacuate the system to at least 29 inHg vacuum. Maintain this vacuum for a minimum of 30 minutes (45-60 minutes recommended for thorough moisture removal). Close the valves and monitor for vacuum hold—pressure should not rise more than 1 inHg over 10 minutes, indicating system integrity.
10. 10

    Recharge AC system with refrigerant
    Using the AC recharge equipment, introduce the specified amount of R-1234yf refrigerant into the system (refer to vehicle label for exact capacity, typically 1.5-2.0 lbs). Add the appropriate amount of PAG oil if not already included in the refrigerant charge (consult service manual for oil capacity based on component replacement). Monitor pressures during charging to ensure proper filling.
11. 11

    Reconnect 12V battery and re-enable high voltage system
    Reconnect the 12V auxiliary battery negative terminal. Using Rivian diagnostic tools and service procedures, properly re-enable the high voltage system and exit service mode. Follow all safety verification steps per Rivian protocols.
12. 12

    Test AC system operation and pressure switch function
    Start the vehicle and activate the climate control system. Set to maximum cooling. Using the AC manifold gauges, verify system pressures are within normal operating range (typically 25-45 psi low side, 150-300 psi high side depending on ambient temperature). Monitor for proper compressor cycling controlled by the high pressure switch. Use diagnostic software to verify the high pressure switch is communicating properly with the HVAC control module.

Reassembly

1. Reinstall the upper panel covering in the front compartment, ensuring all fasteners are properly secured
2. Close the front trunk and verify all panels are flush and properly aligned
3. Clean any refrigerant oil residue from components and surrounding areas

Verification

• Verify AC system pressures are within specification using manifold gauges during operation
• Use a refrigerant leak detector around the new high pressure switch connection to verify no leaks are present
• Confirm cold air output from all cabin vents reaches appropriate temperature (typically 40-50°F at vents)
• Use Rivian diagnostic software to verify no AC system fault codes are present
• Verify high pressure switch signal reads correctly in diagnostic data stream during various operating conditions
• Test AC system at idle and during driving to confirm proper operation under various loads
• Document refrigerant charge amount and verify it matches vehicle specification label

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