Inverter R&R

Remove and replace the power inverter assembly on a 2023 Rivian EDV 500 dual motor AWD electric delivery van, including high voltage system isolation, coolant system draining, and electrical disconnections.

Warnings

Tools required

Parts

• Power inverter assembly × 1 — Use OEM Rivian part number
• High voltage connector seal kit × 1 — Use OEM specification
• Inverter mounting gasket × 1 — Use OEM specification
• Coolant hose O-rings × 4 — Use OEM specification
• High voltage interlock connector × 1 — Use OEM specification if damaged

Fluids

• EV Battery/Motor Coolant — 10 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Ensure vehicle has been off for minimum 2 hours and high voltage system is cool
3. Connect Rivian diagnostic tool and document any existing fault codes
4. Remove front lower underbody panels to access inverter assembly from below
5. Locate high voltage service disconnect (under front hood, driver side) and open service cover

Procedure

1. 1

   Isolate high voltage system
   Using diagnostic tool, command the high voltage system to service mode. Remove the high voltage service disconnect by rotating counterclockwise and pulling straight out. Store disconnect in a secure location away from vehicle. Attach lockout/tagout device to service disconnect location. Verify with multimeter that HV battery pack voltage at inverter connections reads 0V DC. Wait minimum 15 minutes for capacitor discharge.
2. 2

   Disconnect 12V battery
   Locate 12V auxiliary battery in front compartment. Disconnect negative terminal first, then positive terminal. Isolate terminals to prevent reconnection. This prevents control module communication errors and ensures complete electrical isolation.
3. 3

   Drain inverter coolant circuit
   Locate coolant drain valve on inverter cooling circuit (lower front of inverter assembly). Position drain pan beneath vehicle. Open drain valve and allow EV Battery/Motor Coolant to drain completely. Expect approximately 3-4 quarts to drain from inverter circuit. Close drain valve when flow stops.
4. 4

   Disconnect coolant lines from inverter
   Remove spring clamps from coolant inlet and outlet hoses at inverter. Using slight twisting motion, disconnect coolant hoses from inverter ports. Cap or plug open ports immediately to prevent contamination. Inspect O-rings on hoses and note condition for replacement.
5. 5

   Remove high voltage cable shields
   Remove protective shields covering high voltage cable connections at inverter. These are typically secured with quick-release fasteners or 10mm bolts. Set shields aside in clean area. Verify again with multimeter that no voltage is present at HV terminals.
6. 6

   Disconnect high voltage cables
   Wearing insulated high voltage gloves, remove high voltage interlock connector (orange safety connector) from inverter. Then remove mounting bolts securing HV positive and negative bus bars to inverter terminals. Carefully separate HV cables from inverter, supporting cable weight to prevent strain on connections. Cover exposed HV terminals with insulating caps.
7. 7

   Disconnect low voltage control harnesses
   Locate and photograph all low voltage control harness connections to inverter (typically 3-5 connectors). Release connector locks and carefully disconnect each harness. Note connector positions and wire routing. Secure connectors away from work area to prevent damage.
8. 8

   Disconnect motor phase cables
   Remove three motor phase cable connections from inverter output terminals (U, V, W phases for each motor - 6 total connections). Remove retaining hardware and carefully separate phase cables from inverter. Support cable weight and mark each cable position for correct reassembly.
9. 9

   Remove inverter mounting hardware
   Locate all inverter mounting bolts securing unit to subframe or mounting bracket (typically 6-8 mounting points). Support inverter weight with jack or assistant. Remove mounting bolts in cross-pattern sequence to prevent binding. Note any ground strap connections that must be transferred to new inverter.
10. 10

    Remove inverter assembly
    With all connections and fasteners removed, carefully lower inverter assembly from vehicle. Maneuver inverter clear of surrounding components, taking care not to damage coolant ports or electrical terminals. Place removed inverter on clean workspace for inspection and comparison with replacement unit.
11. 11

    Prepare new inverter
    Unpack replacement inverter and verify part number matches original unit. Transfer any mounting brackets, ground straps, or adapter plates from old inverter to new unit if not pre-installed. Install new mounting gasket on inverter mating surface. Apply small amount of dielectric grease to HV terminal contact surfaces.
12. 12

    Install new inverter assembly
    Carefully position new inverter into mounting location, aligning mounting holes with subframe or bracket. Support inverter weight and start all mounting bolts by hand to ensure proper alignment. Torque mounting bolts in cross-pattern sequence. Reconnect ground strap connections securely.
13. 13

    Reconnect motor phase cables
    Reconnect six motor phase cables to correct inverter output terminals (U, V, W for front motor and U, V, W for rear motor). Verify each cable is connected to documented original position. Install and secure all phase cable mounting hardware. Ensure proper cable routing without interference or strain.
14. 14

    Reconnect high voltage cables
    Remove insulating caps from HV terminals. Position HV positive and negative bus bars to inverter terminals and install mounting bolts. Torque HV connection bolts per service procedure. Reconnect high voltage interlock connector. Install HV cable protective shields and secure all fasteners.
15. 15

    Reconnect low voltage harnesses and coolant lines
    Reconnect all low voltage control harnesses to inverter in documented positions, ensuring positive connector lock engagement. Install new O-rings on coolant hose connections. Connect coolant inlet and outlet hoses to inverter and secure with new spring clamps. Verify all connections are secure and properly routed.

Reassembly

1. Reinstall front lower underbody panels using all original fasteners
2. Refill EV Battery/Motor Coolant system through fill port, adding approximately 10 quarts total or until level reaches proper mark
3. Reconnect 12V auxiliary battery (positive terminal first, then negative)
4. Reinstall high voltage service disconnect and rotate clockwise to lock position
5. Cycle vehicle power on and verify no warning lights on instrument cluster
6. Using diagnostic tool, clear service mode and activate high voltage system
7. Command coolant pump operation through diagnostic tool to purge air from cooling system, add coolant as needed
8. Check for coolant leaks at all inverter connections while pump is running

Verification

• Using diagnostic tool, verify communication with inverter control module and confirm correct inverter serial number is registered
• Perform stationary motor function test through diagnostic tool to verify both front and rear motors respond correctly
• Check for any new diagnostic trouble codes related to inverter, motor control, or high voltage system
• Verify coolant level is stable and no leaks are present after running coolant pump for 5 minutes
• Test drive vehicle in controlled environment, verifying smooth acceleration, regenerative braking function, and no unusual noises or vibrations
• Perform final diagnostic scan and verify all high voltage system parameters are within normal operating range
• Document inverter replacement in vehicle service records including new inverter serial number and firmware version

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