Comprehensive electrical system diagnosis procedure for the 2023 Rivian EDV 500 dual motor electric delivery van, including high-voltage and low-voltage system troubleshooting.

Warnings

Tools required

Parts

• 12V auxiliary battery (if diagnosis reveals failure) × 1 — Use OEM specification
• High-voltage contactors (if diagnosis reveals failure) × 1 — Use OEM specification
• Wiring harness connectors (if damaged) × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and apply parking brake
2. Place wheel chocks at all four wheels
3. Ensure vehicle has been off for at least 10 minutes to allow high-voltage capacitors to discharge
4. Verify all high-voltage safety equipment is available and in good condition
5. Review customer complaint and document all symptoms in detail
6. Connect diagnostic scan tool and retrieve all stored fault codes from all modules before beginning
7. Photograph or document any visible damage to wiring, connectors, or components
8. Verify 12V auxiliary battery voltage is above 12.4V; charge if necessary before diagnosis

Procedure

1. 1

   Initial System Scan and Fault Code Retrieval
   Connect the diagnostic scan tool to the OBD-II port located under the driver side dashboard. Perform a complete vehicle scan to retrieve fault codes from all control modules including: Battery Management System (BMS), Drive Inverter Modules (front and rear), Vehicle Control Unit (VCU), Gateway Module, HVAC Controller, and all auxiliary systems. Document all current and pending codes with freeze frame data. Note any communication errors between modules which may indicate network issues.
2. 2

   12V Auxiliary System Verification
   Test the 12V auxiliary battery voltage and load capacity. The EDV 500 uses the high-voltage battery to charge the 12V system through a DC-DC converter. Verify voltage at battery terminals (should be 12.6V-14.4V with vehicle in ready mode). Check all major 12V fuses in the main fuse panel located in the driver footwell area and the auxiliary fuse panel in the rear cargo area. Test DC-DC converter output using diagnostic tool to verify it is supplying proper charging voltage to the 12V system.
3. 3

   High-Voltage Safety Verification and System Status
   Don high-voltage insulated gloves. Locate the high-voltage disconnect service plug under the rear cargo floor access panel. Without removing the plug, use the diagnostic scan tool to verify high-voltage system status. Check that all HV contactors are operating properly. Review BMS data for battery pack voltage (should be 320-400V depending on state of charge), individual cell group voltages (should be within 0.02V of each other), and pack temperature. Any significant voltage imbalance or temperature anomaly indicates a battery pack issue requiring specialized service.
4. 4

   Communication Network Diagnosis
   Using the scan tool, verify communication on all CAN bus networks. The EDV 500 uses multiple CAN networks: High-speed powertrain CAN, chassis CAN, and comfort CAN. Check for U-code (network communication) faults. Use the scan tool's network test function to identify any modules not responding. If communication faults exist, inspect wiring harness connectors at affected modules for corrosion, pin back-out, or water intrusion. Pay special attention to underbody connectors which may be exposed to road debris and moisture.
5. 5

   Drive Motor and Inverter System Check
   Access both front and rear drive inverter data through the diagnostic tool. Review motor temperatures, resolver signals (motor position feedback), and inverter DC bus voltages. Check for any inverter fault codes. If the complaint involves drive performance issues, review motor torque command vs. actual torque delivery data. Verify three-phase motor winding resistance balance using the high-voltage insulated multimeter with HV system properly locked out. Each phase should measure within 5% of other phases.
6. 6

   Charging System Diagnosis
   If charging issues are reported, inspect the charge port located on driver side front fender for damage, debris, or signs of arcing. Use scan tool to access On-Board Charger (OBC) module. Check AC input voltage sensing, DC output current limiting, and charge cycle completion status. Review charge logs for any interruptions or fault events. Verify communication between OBC, BMS, and VCU during a charge session if possible. Check cooling system operation for the OBC as overheating will limit charge rate.
7. 7

   Thermal Management System Check
   The EDV 500 uses a liquid cooling system for the battery pack and drive units. Using diagnostic tool, monitor coolant temperatures for battery and motor circuits. Verify electric coolant pumps are operating when commanded. Check coolant level in reservoirs located in front compartment. Inspect coolant hoses and connections at battery pack interfaces under vehicle for leaks or damage. Review thermal management system fault codes which may indicate sensor failures or valve malfunctions in the cooling distribution system.
8. 8

   Ground and Power Distribution Verification
   Verify integrity of main high-voltage and low-voltage ground connections. The primary HV ground is located at the battery pack; the 12V ground distribution point is at the frame rail behind the driver's seat. Using a multimeter, check voltage drop across ground connections (should be less than 0.1V under load). Inspect main power distribution center for signs of overheating, loose connections, or corrosion. Check all high-current fusible links and main power relays for proper operation.
9. 9

   Sensor and Input Signal Testing
   Based on fault codes and symptoms, test relevant sensor inputs including: accelerator pedal position sensors (should show 0.5V-4.5V range with smooth progression), brake pedal position sensors, vehicle speed sensors at each wheel hub, steering angle sensor, and HVAC temperature sensors. Use scan tool to view live data and verify sensor readings match physical conditions. Check sensor supply voltages (typically 5V or 12V) and ground circuits for proper values.
10. 10

    Accessory System Verification
    Test operation of all electric accessories that may relate to the complaint: power windows, door locks, exterior lighting, interior lighting, HVAC blower and compressor, windshield wipers, and cargo area equipment. Check current draw of accessories using clamp meter to identify any circuits drawing excessive current which could indicate short circuits or failing components. Verify all accessory control modules are responding properly to commands from switches and the central gateway.
11. 11

    Insulation Resistance Testing
    If high-voltage system faults are present, perform insulation resistance testing with HV system properly locked out and discharged. Remove the HV service disconnect. Using a megohmmeter rated for 1000V, test insulation resistance between HV positive and vehicle chassis ground, and HV negative and chassis ground. Readings should exceed 500 ohms per volt of system voltage (minimum 200k ohms for 400V system). Lower readings indicate insulation breakdown requiring immediate investigation of HV cables, connectors, or component internal faults.
12. 12

    Software Version Verification and Updates
    Check all control module software versions against current Rivian technical service bulletins. The EDV 500 may require software updates to address known issues. Using the diagnostic tool with proper security access, check for available calibration updates for BMS, VCU, drive inverters, and gateway modules. Document current software versions in repair notes. Schedule software updates if applicable to reported symptoms.
13. 13

    Specialized Circuit Testing
    Based on diagnosis results, perform targeted testing of specific circuits related to the fault. This may include: testing contactor coil resistance and operation, checking pre-charge resistor circuit function, verifying interlock loop continuity (safety circuit that disables HV system if breached), testing charge port lock mechanism operation, or checking regenerative brake blending system function. Use wiring diagrams specific to the EDV 500 to trace circuits and identify component locations.
14. 14

    Documentation and Root Cause Determination
    Compile all test results, fault codes, and measurement data to determine root cause of the electrical issue. Cross-reference findings with Rivian service information and technical service bulletins. Create a diagnostic report documenting: original complaint, fault codes found, tests performed with results, root cause determination, and recommended repairs. If issue cannot be isolated with available tools, document findings and contact Rivian technical support for guidance on specialized procedures or component-level diagnostics.
15. 15

    Clear Fault Codes and Perform System Reset
    Once diagnosis is complete and any immediate safety concerns are addressed, clear all diagnostic trouble codes from affected modules. Perform a complete system reset using the scan tool if required by diagnostic findings. Verify all modules return to normal ready status. If repairs are deferred, ensure vehicle is safe to operate or clearly tag as out of service. Save diagnostic session data to scan tool or computer for future reference.

Reassembly

1. Reinstall any access panels or covers removed during diagnosis
2. Ensure HV service disconnect is properly installed if it was removed during testing
3. Verify all electrical connectors are fully seated and locked
4. Remove wheel chocks and lower vehicle from lift if raised

Verification

• Perform final scan of all control modules to verify no new fault codes are present
• Verify vehicle enters ready mode without warning lights or messages
• Test drive vehicle if safe to do so, monitoring all electrical systems for proper operation
• Confirm customer complaint symptom is resolved or properly documented for repair
• Verify 12V battery is charging properly from DC-DC converter (voltage should be 13.8-14.4V in ready mode)
• Check that all accessories and systems tested during diagnosis are functioning normally
• Document all findings and recommendations in repair order with specific fault codes and test results

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