Heat Pump System

Complete removal and replacement of the heat pump system assembly, including refrigerant recovery, component replacement, and system recharge for the Rivian EDV 500 dual motor electric vehicle.

Warnings

Tools required

Parts

• Heat pump compressor assembly × 1 — Use OEM specification
• Heat pump condenser/evaporator unit × 1 — Use OEM specification
• Refrigerant line O-rings × 1 — R-1234yf compatible O-ring kit
• PAG oil for R-1234yf system × 1 — Use OEM specification
• R-1234yf refrigerant × 1 — Use OEM specification
• Heat pump electrical connector seals × 1 — Use OEM specification
• Coolant hose clamps × 4 — OEM replacement clamps
• Underbody shield fasteners × 1 — Push-pin retainers

Fluids

• EV Battery/Motor Coolant — 10 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Access high voltage battery disconnect located in rear service panel under cargo area
3. Remove HV battery service disconnect and install lockout device per Rivian service procedures
4. Wait minimum 5 minutes for HV capacitors to discharge
5. Verify zero voltage on HV system using CAT III-rated multimeter at service disconnect points
6. Raise vehicle on lift using manufacturer-specified lift points with EV chassis adapters
7. Remove front underbody shields and aero panels to access heat pump components
8. Place warning tags on steering wheel indicating HV system is disabled
9. Connect R-1234yf recovery machine to service ports on heat pump system
10. Document initial refrigerant charge weight and system pressures before recovery

Procedure

1. 1

   Recover refrigerant from heat pump system
   Connect manifold gauges to low and high side service ports on heat pump assembly located in front compartment. Operate refrigerant recovery machine according to manufacturer instructions until system vacuum is achieved. Recovery typically takes 15-20 minutes. Record amount of refrigerant and oil recovered for recharge calculations.
2. 2

   Drain EV coolant from thermal management system
   Locate coolant drain valve on underbody coolant manifold near front motor assembly. Connect drain hose to valve and route to collection pan. Open drain valve and allow system to gravity drain. System capacity is 10 quarts total. Use coolant evacuation tool to pull remaining coolant from heat pump heat exchanger passages if available.
3. 3

   Disconnect electrical connectors from heat pump components
   Locate main heat pump control module connector on driver side of heat pump assembly. Press release tab and disconnect. Disconnect compressor power connector (orange HV cable with safety interlock). Disconnect temperature sensor connectors (3 total) from heat exchanger and refrigerant lines. Disconnect pressure transducer connectors on high and low side service valves. Label all connectors for reassembly.
4. 4

   Disconnect refrigerant lines from heat pump assembly
   Using appropriate line disconnect tools, separate refrigerant lines at quick-connect fittings. There are four main connections: suction line, discharge line, and two heat exchanger connections. Cap all open refrigerant ports immediately with shipping caps to prevent moisture ingress. Remove and discard all O-rings from fittings.
5. 5

   Disconnect coolant lines from heat pump heat exchanger
   Release spring clamps on two coolant hoses connecting to heat pump heat exchanger using hose clamp pliers. Twist hoses to break seal and pull off fittings. Expect residual coolant spillage. Plug coolant ports on heat exchanger and vehicle-side lines with rubber plugs to prevent contamination.
6. 6

   Remove heat pump mounting fasteners
   Remove four mounting bolts securing heat pump assembly to front subframe. Bolts are located at corners of mounting bracket. Support heat pump assembly weight with transmission jack or suitable support before removing final bolt. Assembly weighs approximately 45 pounds.
7. 7

   Remove heat pump assembly from vehicle
   Carefully lower heat pump assembly on transmission jack while guiding electrical harness and remaining lines clear of component. Maneuver assembly forward and down to remove from vehicle. Note orientation and routing of all connections for reinstallation.
8. 8

   Install new heat pump assembly
   Position new heat pump assembly on transmission jack and raise into position. Align mounting brackets with subframe mounting points. Guide assembly into place while ensuring no wiring or lines are pinched. Install mounting bolts hand-tight initially, then tighten in diagonal pattern. Verify assembly is seated properly against mounting surfaces.
9. 9

   Connect coolant lines to heat pump
   Install new coolant hoses onto heat pump heat exchanger fittings. Ensure hoses are fully seated over barbed fittings. Install new spring clamps positioned 1/4 inch from hose end. Verify clamps are properly engaged and hoses cannot be pulled off by hand.
10. 10

    Connect refrigerant lines with new O-rings
    Install new R-1234yf compatible O-rings on all refrigerant line fittings. Lubricate O-rings lightly with PAG oil specified for system. Connect refrigerant lines to heat pump assembly quick-connect fittings. Push connectors until audible click is heard and verify lock indicator shows proper engagement. Tug test each connection.
11. 11

    Reconnect all electrical connections
    Reconnect all electrical connectors to heat pump components in reverse order of removal. Ensure each connector locks fully and seals are properly seated. Reconnect compressor HV power connector with orange cable, ensuring safety interlock is properly engaged. Reconnect control module connector, temperature sensors, and pressure transducers.
12. 12

    Fill thermal management system with coolant
    Add 10 quarts of EV Battery/Motor Coolant through fill port on coolant reservoir. Use only coolant meeting Rivian specifications. Fill slowly to avoid air pockets. With HV system still disconnected, operate coolant pump using service mode on diagnostic tool to circulate coolant and purge air. Top off coolant as level drops during purging process.
13. 13

    Evacuate and recharge refrigerant system
    Connect vacuum pump to service ports and evacuate system to 500 microns for minimum 45 minutes. System must hold vacuum for 30 minutes without rise to pass leak test. Add specified amount of PAG oil to match oil recovered plus replacement for new components. Charge system with R-1234yf refrigerant to specification using recovery machine in charge mode. Typical charge is 2.8-3.2 pounds but verify with service data.
14. 14

    Perform leak test and system verification
    Use electronic refrigerant leak detector to check all connections, fittings, and component seams for leaks. Check pressure readings on manifold gauges against specifications for ambient temperature. Pressures should stabilize with system off. Reconnect HV battery service disconnect. Clear any diagnostic trouble codes using scan tool. Enable heat pump system through HVAC controls and verify operation.

Reassembly

1. Reinstall all underbody shields and aero panels using new push-pin fasteners where needed
2. Lower vehicle from lift and verify all tools and equipment are removed from work area
3. Remove lockout device from HV battery service disconnect
4. Reconnect HV battery per Rivian service procedures
5. Remove warning tags from steering wheel

Verification

• Start vehicle and verify no warning lights or messages related to thermal management system
• Using Rivian diagnostic tool, verify heat pump system operates in all modes (heating, cooling, defrost)
• Check coolant level in reservoir after system has reached operating temperature and top off if needed
• Verify refrigerant pressures are within specification during operation using manifold gauges
• Test cabin heating and cooling performance at maximum and minimum temperature settings
• Perform electronic leak detection recheck after system has operated for 10 minutes
• Verify all electrical connectors show proper communication with no DTCs stored
• Check for coolant leaks at heat exchanger connections after thermal cycling
• Verify compressor engages and disengages smoothly without abnormal noise or vibration
• Document final refrigerant charge weight and system operating pressures in service records

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