Service or replacement of the high voltage interlock loop (HVIL) circuit components that monitor the integrity of high voltage connections and immediately disable the high voltage system if a disconnection is detected.

Warnings

Tools required

Parts

• HVIL connector seals/gaskets × 1 — Use OEM specification
• HVIL circuit continuity sensor (if faulty) × 1 — Use OEM specification
• High voltage cable HVIL connectors (if damaged) × 1 — Use OEM specification

Preparation

1. Ensure vehicle is parked on level ground in a well-ventilated area with no flammable materials nearby
2. Place warning signs around vehicle indicating high voltage work in progress
3. Verify fire extinguisher is accessible and properly charged
4. Put on insulated high voltage safety gloves and face shield
5. Open driver's door and ensure vehicle is in Park with parking brake applied
6. Power off the vehicle completely using the center display (do not just exit the vehicle)
7. Disconnect the 12V auxiliary battery negative terminal and wait 2 minutes for vehicle systems to power down
8. Connect the diagnostic scan tool and document all active fault codes related to HVIL system
9. Review vehicle service history for any previous high voltage system repairs or HVIL circuit issues

Procedure

1. 1

   Access high voltage service disconnect
   Locate the high voltage service disconnect under the front hood on the driver's side of the battery pack. Remove the plastic service panel cover by releasing the clips. The service disconnect is a bright orange handle with warning labels.
2. 2

   De-energize high voltage system
   Pull the high voltage service disconnect handle straight up and out to physically disconnect the high voltage battery from the vehicle systems. The handle should lock in the removed position. Install the lockout/tagout device through the hole in the disconnect handle to prevent accidental reconnection. Store the disconnect handle in a secure location away from the vehicle.
3. 3

   Wait for capacitor discharge
   Wait a minimum of 15 minutes to allow all high voltage capacitors in the system to fully discharge. Do not touch any orange high voltage cables or components during this waiting period. Set a timer to ensure the full waiting period is observed.
4. 4

   Verify system de-energization
   Using a high voltage capable digital multimeter, verify zero voltage across the high voltage bus bars at the service disconnect location. Measure between positive and negative terminals, then measure each terminal to vehicle ground. All readings must show 0V DC (below 10V is acceptable residual). If voltage is present above 10V, wait an additional 10 minutes and retest. Document all voltage readings.
5. 5

   Locate HVIL circuit components
   Identify all HVIL circuit connectors throughout the high voltage system. On the EDV 500, these are located at: the battery pack service disconnect, the front motor inverter connection, the rear motor inverter connection, the HV junction box, and the onboard charger connection. HVIL connectors are small low-voltage connectors (typically 2-pin) adjacent to the main orange high voltage connectors.
6. 6

   Inspect HVIL connectors
   Carefully inspect each HVIL connector for damage, corrosion, water intrusion, bent pins, or loose connections. The HVIL circuit is a continuous low-voltage loop that runs through all high voltage connections. Any break in this loop will trigger a fault and disable the high voltage system. Check connector seals for proper seating and signs of water infiltration. Document the condition of each connector with photos if issues are found.
7. 7

   Test HVIL circuit continuity at service disconnect
   At the high voltage service disconnect location, locate the HVIL circuit test points (typically labeled or shown in service documentation). Using a multimeter set to resistance mode, measure the continuity of the HVIL loop with all high voltage connectors connected (except the service disconnect which must remain removed). A properly functioning HVIL circuit should show a specific resistance value between 100-500 ohms (consult service data for exact specification). Infinite resistance indicates an open circuit fault.
8. 8

   Perform individual connector testing
   If the HVIL circuit shows an open circuit, systematically disconnect and inspect each HVIL connector to isolate the fault. Start at the battery pack and work toward the motors and charger. After disconnecting each connector, measure resistance across the pins on both the male and female sides. Compare readings to service specifications. This will identify which connector or cable section has failed.
9. 9

   Service or replace faulty components
   If a HVIL connector is corroded or damaged, clean the terminals with electrical contact cleaner and a soft brush, or replace the connector if damaged beyond repair. If water intrusion is found, inspect the cable routing and seals to identify the entry point. Replace any damaged seals or gaskets. If the HVIL circuit sensor or monitoring module itself is faulty (typically indicated by diagnostic codes), replace the component per Rivian service procedures.
10. 10

    Reconnect and seal all HVIL connectors
    Reconnect all HVIL connectors in reverse order of removal. Ensure each connector clicks fully into place and the locking mechanism engages. Apply dielectric grease to connector seals if specified by the manufacturer. Verify that all connector seals and boots are properly seated to maintain IP67 water resistance rating. Double-check that no HVIL connectors were left disconnected.
11. 11

    Verify HVIL circuit integrity
    With all HVIL connectors reconnected (service disconnect still removed), measure HVIL circuit resistance again at the service disconnect test points. The resistance should now read within the specified range (typically 100-500 ohms). If the reading is still infinite or out of range, recheck all connections and repeat diagnostic steps. Document the final resistance reading.
12. 12

    Reinstall high voltage service disconnect
    Remove the lockout/tagout device. Carefully reinstall the high voltage service disconnect handle, ensuring it seats fully and locks into place. You should feel and hear a positive engagement. The orange handle should be flush with the surrounding surface when properly installed. Do NOT force the disconnect if it does not seat easily—this indicates misalignment.
13. 13

    Reconnect 12V battery and initialize system
    Reconnect the 12V auxiliary battery negative terminal. Wait for the vehicle systems to initialize (approximately 2 minutes). The vehicle may perform self-checks during this time. Keep hands clear of high voltage components during initialization even though system should remain safe.
14. 14

    Clear codes and perform system test
    Using the diagnostic scan tool, clear all HVIL-related fault codes only after verifying all repairs are complete. Command the high voltage system to energize using the scan tool's active test function. Monitor the HVIL circuit status in live data—it should show 'Circuit Closed' or 'OK' status. If HVIL faults return immediately, de-energize the system and repeat diagnostic steps.
15. 15

    Perform final high voltage system verification
    With the scan tool monitoring, power on the vehicle and verify the high voltage system initializes without faults. Check that the READY indicator appears on the dashboard. Test drive the vehicle briefly (if safe to do so) and verify normal operation of both drive motors. Return to the shop and perform a final scan for any pending or stored HVIL codes. Document all final test results and resistance readings in the vehicle service record.

Reassembly

1. Reinstall the high voltage service disconnect cover panel and secure all clips
2. Verify all high voltage cable routing matches factory configuration with no interference or stress on connections
3. Ensure all HVIL connector boots and seals are properly positioned for weather protection
4. Remove all lockout/tagout devices and warning signs from the vehicle
5. Clean and properly store all insulated tools and safety equipment

Verification

• Confirm HVIL circuit resistance is within specification (typically 100-500 ohms) with all connections installed
• Verify no HVIL-related diagnostic trouble codes are present or pending after clearing and road test
• Confirm high voltage system energizes properly and READY indicator appears on dashboard
• Verify both front and rear drive motors operate normally under load during test drive
• Check that charging function initializes properly if onboard charger was part of HVIL service
• Document all voltage measurements, resistance readings, and final diagnostic scan results in repair order
• Verify vehicle can be powered on and off multiple times without HVIL faults returning

More procedures for this vehicle