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.
- 2026-03-18: Released new procedure.
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Prepare for HV battery removal
NoteDue 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
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Remove all items from pockets and ensure not wearing metal items
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Inspect HV insulating gloves
NoteCheck gloves for damage prior to use, Refer to service document TN-15-92-003, for information on inspecting HV gloves.
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Put on HV insulating gloves and leather over gloves
NoteUse 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.
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Secure vehicle outside of workshop
NoteSecure vehicle in an outdoor area with 15M of space around it in every direction
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Install wheel chocks onto rear wheels
NoteSee HV battery RR procedure for steps
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Release electronic parking brakes
NoteSee HV battery RR procedure for steps
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Download and Install PCAN driver
NoteAfter software has been downloaded install drivers to laptop.
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Connect CAN dongle to laptop via USB port
Note1x connector, WARNING: Do not place anything on top of the HV battery other than the high voltage “Danger” placard
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Connect CAN breakout harness to vehicle
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Connect Powertrain connector of CAN breakout harness to PCAN-USB adapter
Note1x connector
- Log into toolbox
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Open HV Battery Communication Tool in Toolbox
NoteNavigate to the HV Battery Communication Tool on the left hand Toolbox menu
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Check that PCAN is detected by laptop
NoteIf 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."
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Select ECU
NoteSelect HVBMS ECU in drop down menu
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Check HV Battery vitals
NoteRefer 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.
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Disconnect CAN dongle from laptop
Note1x connector, WARNING: Do not place anything on top of the HV battery other than the high voltage “Danger” placard
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Disconnect CAN breakout harness from vehicle
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Power down vehicle
NoteRefer to HV battery RR procedure for steps
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Prepare work area
NotePrepare a workspace around a two post lift with nearby access to HV PPE, Battery table, and necessary tooling
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Raise vehicle fully and lower lift onto locks
NoteSet 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
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Inspect HV battery for dents, fluid leaks, or other signs of instability
NoteIf found, refer to Toolbox article 5402800
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Inspect HV battery for coolant leaks or fluid ingress
NoteRefer 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
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Remove HV battery from vehicle
NoteRefer to HV battery removal procedure for applicable vehicle model
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Move HV battery to a suitable work area
NoteHv battery must have 15M of space around it in every direction
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Remove high voltage battery pyro disconnect
NoteSee HV battery RR procedure for steps
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Remove LH side rail ski
NoteRemove the clamps and pull the LH side rail ski away from the HV battery and pivot it downwards to remove
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Remove RH side rail ski
NoteRemove the clamps and pull the RH side rail ski away from the HV battery and pivot it downwards to remove
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Remove all umbrella valves from HV battery
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Place HV Danger placard on top of battery
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Place barricades around work area
NoteNote location of extinguishers and HV rescue hook
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Ensure entire work area is clear
NoteIncluding above and below battery
- Remove HV insulating gloves