AC Recharge

Recover, evacuate, and recharge the R-1234yf A/C system on a 2024 Model S Plaid. This is a service-interval task that maintains cabin cooling and HV battery thermal management performance.

Warnings

Tools required

Parts

• R-1234yf refrigerant (charge amount per under-hood label) × 1 — R-1234yf — SAE J2845 spec
• PAG oil compatible with R-1234yf and electric A/C compressors (ND-oil/POE-equivalent as specified by Tesla) × 1 — Electric-compressor-safe lubricant — verify label spec
• Service port valve core caps (R-1234yf unique fitting) × 2 — OEM replacement caps

Preparation

1. Park on level ground, place in P, engage parking brake.
2. Exit ALL doors with the key fob away from the vehicle. Wait at least 2 minutes for HV systems to fully de-energize, even on this non-HV job.
3. Disconnect the 12V low-voltage battery in the frunk under the nose cowl panel (or the 16V Li-ion under the rear seat if equipped on this Plaid build — verify before proceeding).
4. DO NOT touch, cut, or pierce ANY orange cable — these are high-voltage and lethal.
5. If at any point you encounter an orange cable, an HV component, or are unsure if a system is de-energized: STOP and consult a Tesla-certified technician.
6. Locate the under-hood/frunk A/C service label and record the specified refrigerant type (R-1234yf) and total charge weight in grams.
7. Set HVAC to OFF before powering down the vehicle — do not run climate during service.
8. Allow the system to stabilize at ambient temperature (~20°C / 68°F) for accurate charge measurement.
9. Verify recovery machine is calibrated, oil separator is empty, and tanks are within service date.

Procedure

1. 1

   Locate A/C service ports
   Open the frunk. Locate the high-side and low-side R-1234yf service ports on the A/C lines routed through the front compartment. Ports use unique R-1234yf SAE fittings — they will not accept R-134a couplers. Remove the protective caps and inspect the Schrader valves for damage or oil residue (sign of a leak).
2. 2

   Identify refrigerant
   Connect a refrigerant identifier to the low-side port and confirm the system contains R-1234yf at acceptable purity (>98%). If contaminated or unknown, do not proceed with normal recovery — use a contaminated-refrigerant recovery process to avoid ruining your machine.
   ⚠Air contamination above 2% indicates a leak or improper prior service — find and fix before recharging.
3. 3

   Connect recovery/recharge machine
   With the vehicle OFF and 12V disconnected, connect the high-side and low-side couplers from the R-1234yf-rated recovery machine to the corresponding service ports. Ensure couplers are fully seated and locked.
4. 4

   Recover existing refrigerant
   Run the recovery cycle per the machine's instructions. Record the recovered weight — compare against the label specification. A significant shortfall indicates a leak that must be located and repaired before recharging. Drain and measure any recovered oil; replace an equal amount of fresh electric-compressor-safe PAG/POE lubricant during charging.
   ⚠If less than ~70% of spec charge is recovered, perform leak detection before continuing.
5. 5

   Evacuate the system
   Pull a deep vacuum to at least 500 microns and hold for a minimum of 30 minutes to verify no rise (indicates dryness and no leaks). On a hot/humid day, extend vacuum time. If vacuum will not hold, locate the leak before proceeding — do not 'top off' a leaking electric-compressor system.
   ℹ️Tesla's heat-pump-integrated systems are sensitive to moisture; a thorough vacuum is critical to desiccant longevity.
6. 6

   Add lubricant (if required)
   If oil was lost during recovery or component service, inject the manufacturer-specified electric-compressor-safe lubricant in the exact amount recovered. Do NOT use generic PAG46/PAG100 from a parts-store can — these are typically not low-conductivity rated.
   ⚠️Wrong oil = HV compressor insulation breakdown = thousands of dollars in damage and possible HV fault.
7. 7

   Charge by weight
   Charge the system with R-1234yf to the exact gram weight specified on the under-hood label, measured by the machine's scale. Charge through the high side with the system off (preferred), or per machine instructions. Do not charge by pressure alone — Tesla heat-pump systems will not show normal R-134a-style pressure curves.
   ⚠Overcharging causes high head pressures and can fault the HV compressor controller, triggering thermal-management warnings.
8. 8

   Disconnect machine and reinstall caps
   Close machine valves, disconnect couplers carefully to minimize refrigerant loss, and install new service-port caps with intact seals. The caps are the secondary seal — do not omit them.

Reassembly

1. Confirm both service port caps are installed and torqued snug by hand (no tool spec — these are hand-tight).
2. Reconnect the 12V (or 16V) low-voltage battery.
3. Close the frunk.
4. Power the vehicle on and allow the BMS/HVAC modules to re-initialize (1-2 minutes).

Verification

• Start the vehicle, set climate to LO / max A/C, fan on high, recirculation on.
• After 5 minutes of operation, measure center-vent outlet temperature — expect roughly 4-8°C (40-46°F) at ~21°C (70°F) ambient with low humidity.
• Use the Service Mode (if accessible) or check the touchscreen for any HVAC, thermal, or compressor fault messages — there should be none.
• Listen for compressor cycling/whining; the electric compressor should run smoothly with no clicking or pulsing.
• Recheck high/low side pressures with gauges briefly to confirm they are within the expected R-1234yf operating range for current ambient — then remove gauges and reinstall caps.
• Perform a leak check around all service ports and any previously serviced fittings with an electronic leak detector.
• Inform owner: Tesla does not publish a fixed A/C service interval, but the cabin air filter should be replaced every 2 years (every 3 years on HEPA-equipped Model S with bioweapon defense). Recommend brake fluid check (every 2 years) and battery coolant inspection (4 yr / 50k mi) if due.

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