Inverter R&R

Complete removal and replacement of the power inverter assembly on a 2022 Rivian EDV 500, including high-voltage system isolation, coolant system drainage, and electrical disconnection.

Warnings

Tools required

Parts

• Power inverter assembly × 1 — Use OEM specification
• Inverter coolant inlet O-ring × 1 — Use OEM specification
• Inverter coolant outlet O-ring × 1 — Use OEM specification
• High-voltage connector seal kit × 1 — Use OEM specification
• Inverter mounting gasket × 1 — Use OEM specification
• Cable tie wraps × 10 — Various sizes

Fluids

• EV Battery/Motor Coolant — 10 qt

Preparation

1. Park vehicle on level surface and apply parking brake
2. Ensure vehicle has been off for minimum 30 minutes and high-voltage system is cool
3. Access Rivian service mode through diagnostic tool to disable high-voltage system
4. Disconnect 12V auxiliary battery negative terminal and wait 5 minutes
5. Remove front underbody panels to access inverter assembly from below
6. Place coolant drain pan beneath inverter coolant connections
7. Verify all high-voltage personal protective equipment is in good condition and properly rated

Procedure

1. 1

   Perform high-voltage system lockout
   Using the Rivian diagnostic tool, place the vehicle in service mode and disable the high-voltage system. Remove the high-voltage service disconnect located in the rear compartment by turning counterclockwise and pulling straight out. Store the service disconnect in a secure location away from the vehicle. Install lockout/tagout device on service disconnect location. Wait minimum 15 minutes for capacitor discharge.
2. 2

   Verify high-voltage system de-energization
   Don high-voltage insulated gloves. Using a properly rated digital multimeter, measure voltage at the high-voltage busbar terminals accessible through the service port. Verify reading is 0V DC. Check voltage between positive and negative DC bus terminals at the inverter housing inspection port. Only proceed if voltage reads 0V. Document voltage readings.
3. 3

   Drain inverter coolant circuit
   Locate the coolant drain valve on the inverter coolant circuit (front of motor compartment). Attach drain hose to valve and route to drain pan. Open drain valve and allow coolant to drain completely (approximately 10 quarts). Once drained, close drain valve. Loosen coolant pressure cap on expansion tank to relieve any remaining system pressure.
4. 4

   Disconnect low-voltage control harnesses
   Locate the low-voltage control connector on the inverter assembly (typically marked with gray or black connector housing). Release connector lock tab and disconnect. Label or photograph connector orientation. Disconnect temperature sensor harness from inverter housing. Disconnect resolver or encoder feedback connectors from both front and rear motor assemblies that route through inverter control system.
5. 5

   Disconnect coolant lines from inverter
   Position drain pan to catch residual coolant. Loosen hose clamps on inlet and outlet coolant hoses connected to inverter housing. Carefully twist hoses while pulling to remove from inverter fittings. Expect additional coolant drainage. Cap or plug coolant line ends and inverter ports to prevent contamination. Remove and inspect O-rings on inverter coolant ports.
6. 6

   Disconnect high-voltage DC input cables
   Wearing high-voltage insulated gloves, locate the high-voltage DC input cables (orange cables) connected to the inverter DC terminals. Remove protective covers from DC terminal connections. Using appropriate socket, remove DC positive cable terminal bolt and carefully lift cable away from terminal. Secure cable away from work area. Repeat for DC negative cable. Inspect terminals for any signs of arcing or damage.
7. 7

   Disconnect high-voltage AC output cables to motors
   Locate the three-phase AC output terminals on the inverter assembly (typically marked U, V, W for each motor). Remove protective covers. Remove AC phase cable terminal bolts one at a time, lifting each cable away and securing it out of the work area. Label each cable position (front motor U/V/W, rear motor U/V/W) if not already permanently marked. There will be 6 total AC phase connections for the dual-motor configuration.
8. 8

   Remove inverter mounting hardware
   Support inverter assembly with engine hoist or lift table positioned beneath unit. Locate all inverter mounting bolts (typically 6-8 bolts securing inverter to chassis/subframe). Remove mounting bolts in a cross-pattern to maintain even pressure. Check for any ground straps or additional mounting brackets that must be disconnected. Keep all mounting hardware organized for reinstallation.
9. 9

   Remove inverter assembly from vehicle
   With all connections and mounting hardware removed, carefully lower inverter assembly using hoist or lift table. Maneuver inverter out from underneath vehicle, being careful not to damage cooling fins, connectors, or remaining vehicle components. Place inverter on clean, protected work surface. Inspect mounting area on vehicle for any debris or damage.
10. 10

    Prepare replacement inverter for installation
    Unpack new inverter assembly and verify part number matches vehicle specification. Inspect all terminals, connectors, and mounting surfaces for shipping damage. Install new coolant port O-rings with light coating of fresh EV coolant. Install new mounting gasket if applicable. Transfer any brackets or hardware from old inverter if specified by service information. Verify all protective caps are removed from electrical terminals before installation.
11. 11

    Install new inverter assembly
    Using hoist or lift table, carefully maneuver new inverter into position under vehicle. Align inverter mounting holes with chassis/subframe mounting points. Install mounting bolts finger-tight initially. Once all bolts are started, torque mounting bolts in cross-pattern sequence. Ensure inverter is seated flush against mounting surface and ground connections are clean and tight.
12. 12

    Reconnect high-voltage AC motor cables
    Clean all AC cable terminals and inverter terminal posts with electrical contact cleaner. Reconnect three-phase AC cables to correct motor terminals (U, V, W) for front motor, then rear motor. Follow documented cable positions from disassembly. Install terminal bolts and torque per specification. Verify no cables are twisted or stressed. Install protective covers over AC terminals.
13. 13

    Reconnect high-voltage DC input cables
    Clean DC cable terminals and inverter DC bus terminals. Position DC negative cable on terminal and install bolt, torque per specification. Position DC positive cable on terminal and install bolt, torque per specification. Verify cables are routed in original positions with proper clearance. Install protective covers over DC terminals. Perform visual inspection for proper cable seating and no exposed conductors.
14. 14

    Reconnect coolant lines and low-voltage harnesses
    Remove caps from coolant lines and inverter ports. Connect inlet coolant hose to inverter inlet port and secure with new hose clamp. Connect outlet coolant hose and secure with new hose clamp. Reconnect all low-voltage control harnesses, temperature sensors, and feedback connectors. Ensure all connectors are fully seated and locking tabs are engaged. Verify proper routing of all wiring harnesses away from sharp edges and heat sources.
15. 15

    Fill and bleed coolant system
    Fill EV coolant expansion tank with fresh EV Battery/Motor Coolant to proper level. Using vacuum pump tool, evacuate air from coolant system through specified bleeding ports. Start coolant pump using diagnostic tool with high-voltage system still disabled. Monitor coolant level and add as necessary. Continue bleeding process until no air bubbles are observed. Verify coolant level is correct when system is at operating temperature.

Reassembly

1. Reinstall front underbody panels and secure all fasteners
2. Remove lockout/tagout device and reinstall high-voltage service disconnect
3. Reconnect 12V auxiliary battery negative terminal
4. Using diagnostic tool, perform inverter initialization and configuration procedures
5. Clear any diagnostic trouble codes and exit service mode

Verification

• Using diagnostic tool, verify inverter communication is established and no fault codes are present
• Verify coolant system pressure holds and no leaks are present at inverter connections
• Perform high-voltage insulation resistance test - should read greater than 500 megohms to ground
• Verify all high-voltage connections are properly torqued and secured with protective covers installed
• Perform stationary motor rotation test using diagnostic tool to verify proper inverter operation and phase sequence
• Test drive vehicle to verify normal operation under various load conditions - acceleration, regenerative braking, and highway speed
• Monitor inverter temperatures using diagnostic tool during test drive - should remain within normal operating range
• Recheck coolant level after test drive and top off if necessary
• Perform final visual inspection of all connections and verify no warning lights are present on instrument cluster

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