2026-03-18

Low Internal Isolation Diagnostics - HV System (Test)

Correction code 44500300600 0.90 NOTE: Unless otherwise explicitly stated in the procedure, the correction code and FRT listed above reflect all of the work required to perform this procedure, including the linked procedures. Do not stack correction codes unless explicitly told to do so. NOTE: See Flat Rate Times to learn more about FRTs and how they are created. NOTE: See Personal Protection to make sure you are wearing proper PPE when performing the procedure below. NOTE: See Ergonomic Precautions for safe and healthy working practices.

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Warning
This procedure is a DRAFT. Although it has been validated, Warnings and Cautions might be missing. Follow safety requirements and use extreme caution when working on or near High Voltage systems and components.
  • 2026-03-18: Released new procedure.
  1. Prepare for HV battery removal
    Informational PurposesAn informational icon, calling your attention
    Note
    Due to the potential issues associated with an isolation fault, customer and/or insurance approval is not needed to remove the HV battery while investigating the fault, For high voltage battery packs that have a low internal isolation condition and/or liquid ingress, It is crucial to remove the fluid promptly, HV gloves, Leather over-gloves, Safety glasses, And safety shoes must be worn at all times while handling a vehicle and/or HV battery pack with an internal isolation condition, Refer to Toolbox article 7410000
  2. Remove all items from pockets and ensure not wearing metal items
  3. Inspect HV insulating gloves
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    Note
    Check gloves for damage prior to use, Refer to service document TN-15-92-003, for information on inspecting HV gloves.
  4. Put on HV insulating gloves and leather over gloves
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    Note
    Use HV cut resistant insulated gloves or HV insulating gloves and leather over gloves, HV Insulating gloves must be worn any time a Hioki Tester or Hi-Pot Tester is used, Refer to service document TN-15-92-003 R5 for PPE requirements depending on vehicle configuration.
  5. Secure vehicle outside of workshop
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    Note
    Secure vehicle in an outdoor area with 15M of space around it in every direction
  6. Install wheel chocks onto rear wheels
    Informational PurposesAn informational icon, calling your attention
    Note
    See HV battery RR procedure for steps
  7. Release electronic parking brakes
    Informational PurposesAn informational icon, calling your attention
    Note
    See HV battery RR procedure for steps
  8. Power down vehicle
    Informational PurposesAn informational icon, calling your attention
    Note
    Refer to HV battery RR procedure for steps
  9. Download and Install PCAN driver
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    Note
    After software has been downloaded install drivers to laptop.
  10. Connect CAN dongle to laptop via USB port
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    Warning
    Do not place anything on top of the HV battery other than the high voltage “Danger” placard
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    Note
    1x connector
  11. Connect HV battery communication harness to HVC and CAN dongle
    Warning IconA warning icon, calling your attention to a possibly risky situation
    Warning
    Do not place anything on top of the HV battery other than the high voltage “Danger” placard
    Informational PurposesAn informational icon, calling your attention
    Note
    2x connector, ensure the PCAN is connected to the VEH CAN breakout
  12. Connect battery communication harness to power supply
    Warning IconA warning icon, calling your attention to a possibly risky situation
    Warning
    Do not place anything on top of the HV battery other than the high voltage “Danger” placard
    Informational PurposesAn informational icon, calling your attention
    Note
    Use the 12V output of the power bank
  13. Connect phone to charging cable and charging cable to power supply
    Warning IconA warning icon, calling your attention to a possibly risky situation
    Warning
    Do not place anything on top of the HV battery other than the high voltage “Danger” placard
    Informational PurposesAn informational icon, calling your attention
    Note
    2x connector, Press ''ON'' to turn ON the power bank. This is necessary to prevent the power bank from shutting down automatically if only connected to the BMS, which does not draw enough power for the power bank to remain powered / active.
  14. Open HV Battery Communication Tool in Toolbox
    Informational PurposesAn informational icon, calling your attention
    Note
    Navigate to the HV Battery Communication Tool on the left hand Toolbox menu
  15. Check that PCAN is detected by laptop
    Informational PurposesAn informational icon, calling your attention
    Note
    If PCAN is detected there will be a message on top of the HV Battery Communication Tool, "Select an ECU depending on the HV battery type. Press the Help button for more info on ECU compatibility."
  16. Select ECU
    Informational PurposesAn informational icon, calling your attention
    Note
    Select HVBMS ECU in drop down menu
  17. Check HV Battery vitals
    Informational PurposesAn informational icon, calling your attention
    Note
    Refer to Toolbox article 41977, The HV vitals are not stable if any of the following is true:Module temperatures are significantly higher than ambient temperature.Module temperatures min and max deviate from each other more than 5 degrees C.Brick voltages min and max deviate more than 20 mV.If vitals are not stable, isolate the pack or vehicle in 30 meter bubble.
  18. Disconnect phone and phone charging cables from power supply
    Warning IconA warning icon, calling your attention to a possibly risky situation
    Warning
    Do not place anything on top of the HV battery other than the high voltage “Danger” placard
    Informational PurposesAn informational icon, calling your attention
    Note
    2x connector
  19. Disconnect battery communication harness from power supply
    Warning IconA warning icon, calling your attention to a possibly risky situation
    Warning
    Do not place anything on top of the HV battery other than the high voltage “Danger” placard
    Informational PurposesAn informational icon, calling your attention
    Note
    1x connector
  20. Disconnect HV battery communication harness from HVC and CAN dongle
    Warning IconA warning icon, calling your attention to a possibly risky situation
    Warning
    Do not place anything on top of the HV battery other than the high voltage “Danger” placard
    Informational PurposesAn informational icon, calling your attention
    Note
    2x connectors
  21. Disconnect CAN dongle from laptop
    Informational PurposesAn informational icon, calling your attention
    Note
    1x connector
  22. Prepare work area
    Informational PurposesAn informational icon, calling your attention
    Note
    Prepare a workspace around a two post lift with nearby access to HV PPE, Battery table, and necessary tooling
  23. Remove high voltage battery pyro disconnect
    Informational PurposesAn informational icon, calling your attention
    Note
    See HV battery RR procedure for steps
  24. Remove rocker covers
    Informational PurposesAn informational icon, calling your attention
    Note
    Refer to removal steps in HV battery RR procedure
  25. Install Universal Lift Pad Adapters onto lift arms
    Informational PurposesAn informational icon, calling your attention
    Note
    4x adapters, Refer to removal steps in HV battery RR procedure
  26. Raise vehicle fully and lower lift onto locks
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    Note
    Set vehicle to comfortable working height, Ensure an audible click of locks on both sides is heard before lowering, Vehicle may tilt to the side if both locks are not engaged
  27. Inspect HV battery for dents, fluid leaks, or other signs of instability
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    Note
    If found, refer to Toolbox article 7396600
  28. Inspect HV battery for coolant leaks or fluid ingress
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    Note
    Refer to Toolbox article 40073, If liquid ingress is found then proceed to HV battery removal, If HV battery removal is not possible continue procedure with pack in vehicle, Continue to relevant procedure for fluid ingress removal as needed
  29. Remove rear battery enclosure skid plate from HV battery pack
    Informational PurposesAn informational icon, calling your attention
    Note
    See HV battery RR procedure for steps
  30. Remove LH flood port 2.0 from HV battery
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    Note
    8x tabs, Rotate as needed so that the relief is accessible, Pry between the enclosure and flood port
  31. Remove RH flood port 2.0 from HV battery
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    Note
    8x tabs, Rotate as needed so that the relief is accessible, Pry between the enclosure and flood port
  32. Remove HV battery breather assemblies
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    Note
    6 nuts, 10 mm, 9 Nm
  33. Inspect HV battery for moisture ingress
    Informational PurposesAn informational icon, calling your attention
    Note
    Inspect breather and interior of battery for moisture ingress, If moisture ingress is present then proceed to HV battery replacement
  34. Remove HV battery from vehicle
    Informational PurposesAn informational icon, calling your attention
    Note
    Refer to HV battery removal procedure for applicable vehicle model
  35. Move HV battery to a suitable work area
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    Note
    Hv battery must have 15M of space around it in every direction
  36. Place HV Danger placard on top of battery
  37. Place barricades around work area
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    Note
    Note location of extinguishers and HV rescue hook
  38. Ensure entire work area is clear
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    Note
    Including above and below battery
  39. Remove HV insulating gloves