Pyrotechnic Fuse Inspection

Visual and functional inspection of the high voltage battery pyrotechnic disconnect fuses to ensure proper safety system integrity and compliance with manufacturer service intervals.

Warnings

Tools required

Parts

• Pyrotechnic fuse assembly × 1 — Use OEM specification - replace only if damaged
• HV connector seals × 2 — Use OEM specification - replace if damaged
• Cable tie wraps × 4 — Use OEM specification

Preparation

1. Park vehicle on level surface and apply parking brake
2. Verify vehicle has been off for minimum 15 minutes before beginning work
3. Ensure 12V battery is fully charged to maintain vehicle systems during procedure
4. Connect Rivian diagnostic software and verify no pre-existing high voltage fault codes
5. Document current vehicle state with photographs
6. Verify HV safety equipment is in date and properly rated (insulated gloves, face shield, tools)
7. Review vehicle-specific HV component locations in service documentation
8. Ensure fire extinguisher rated for electrical fires is readily accessible
9. Place high voltage warning signs around vehicle work area

Procedure

1. 1

   Disable high voltage system
   Using Rivian diagnostic software, place the vehicle into service mode to disable the high voltage system. Verify on the diagnostic interface that HV system is completely de-energized and all contactors are open. The pyrotechnic fuse disconnect status should show as 'Ready' not 'Deployed'.
2. 2

   Remove cargo area access panels
   Remove the rear cargo area floor panels to access the high voltage battery compartment. On the EDV 500, remove the left side cargo panel fasteners and carefully lift the panel away. The pyrotechnic fuse assembly is located on the forward left corner of the battery pack assembly.
3. 3

   Verify system de-energization
   Don insulated gloves and face shield. Using the high voltage capable multimeter with insulated test leads, verify zero voltage between HV positive and negative bus bars at the battery disconnect point. Also verify zero voltage between HV positive/negative and chassis ground. Voltage reading must be below 5V DC on all measurements.
4. 4

   Remove pyrotechnic fuse protective cover
   Locate the orange protective cover over the pyrotechnic fuse assembly. Remove the cover fasteners using insulated tools and carefully lift the cover straight up to expose the fuse assembly. Inspect the cover for any signs of heat damage, discoloration, or melting.
5. 5

   Inspect pyrotechnic fuse connectors
   Visually inspect the electrical connectors to the pyrotechnic fuse initiator. Check for corrosion, bent pins, damaged seals, or any signs of moisture intrusion. Verify the connector lock mechanism is intact and properly engaged. Check that the orange high voltage warning labels are present and legible.
6. 6

   Inspect fuse housing and mounting
   Examine the pyrotechnic fuse body for any cracks, deformation, or signs of impact damage. Check mounting brackets for proper torque and security - they should have no movement when hand-checked. Look for any discoloration indicating heat exposure or electrical arcing. Verify no foreign debris or contamination is present around the assembly.
7. 7

   Inspect high voltage cable connections
   Examine the high voltage cable connections on both sides of the pyrotechnic fuse. Check for proper cable routing, adequate clearance from sharp edges, and secure retention of cable management clips. Look for any signs of cable insulation damage, crushing, or abrasion. Verify orange HV cable identification is intact.
8. 8

   Check initiator circuit resistance
   Using the multimeter, disconnect the initiator connector from the pyrotechnic fuse. Measure the resistance of the initiator circuit at the fuse side of the connector. Resistance should read between 1.8 and 2.2 ohms. Values outside this range indicate a compromised fuse that must be replaced. Document the reading.
9. 9

   Verify deployment circuit integrity
   With the initiator connector still disconnected, use the multimeter to check for continuity in the vehicle harness side deployment circuit. There should be no short to ground or to power. Resistance to ground should read greater than 10 megohms. Reconnect the initiator connector ensuring it clicks into place securely.
10. 10

    Inspect ventilation and drainage paths
    Check that the pyrotechnic fuse compartment ventilation openings are clear and unobstructed. Verify drainage ports are not blocked by debris or corrosion. The fuse assembly must have adequate ventilation to prevent moisture accumulation and to vent gases in the event of deployment.
11. 11

    Document inspection findings
    Photograph the pyrotechnic fuse assembly from multiple angles showing overall condition, connector condition, and any areas of concern. Record all measurement values in the vehicle service record. Note the fuse serial number and installation date from the label on the fuse body. Compare findings against previous inspection records if available.
12. 12

    Reinstall protective cover
    Ensure the pyrotechnic fuse area is clean and free of tools or debris. Reinstall the orange protective cover, aligning it properly with mounting points. Install and hand-tighten fasteners in a cross pattern to ensure even seating, then torque to specification per service manual. Verify cover is fully seated with no gaps.
13. 13

    Restore vehicle systems
    Using Rivian diagnostic software, exit service mode and restore normal high voltage system operation. Monitor the diagnostic interface as the system re-energizes. Verify all HV contactors close properly and battery voltage stabilizes at expected levels (typically 350-420V depending on state of charge).
14. 14

    Clear diagnostic codes and verify operation
    Clear any service mode related diagnostic trouble codes using the Rivian diagnostic software. Perform a system health check through the diagnostic software. Verify no new fault codes are present related to the pyrotechnic fuse system, HV battery, or safety circuits. Confirm the pyrotechnic fuse status shows 'Ready' and deployment circuit shows normal.

Reassembly

1. Reinstall all cargo area floor panels and secure all fasteners
2. Verify no tools or equipment have been left in the vehicle
3. Remove high voltage warning signs from work area
4. Update vehicle service records with inspection date, findings, and all measurement values
5. If any anomalies were found, document them clearly and escalate per manufacturer guidelines

Verification

• Perform final scan with Rivian diagnostic software confirming no active fault codes
• Verify pyrotechnic fuse deployment circuit shows normal status with no faults
• Test vehicle in READY mode to confirm high voltage system operates normally
• Verify propulsion system engages properly with no warning lights on instrument cluster
• Confirm all cargo panels are properly secured and no rattles are present
• Document completion of inspection in vehicle service history with technician certification

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