2026-08-09

AC Junction Box (Standard) (Remove and Replace)

Correction code NEW 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.

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.
Warning
Cybertruck electronics are powered by a 48V "mid voltage" or "MV" architecture that is designed to improve efficiency. Servicing MV components requires extra knowledge and care in order to avoid personal and/or vehicular harm. Read and understand MV precautions in Electrical Precautions and make sure any required MV-related training courses have been completed, as applicable.
Warning
Only technicians who have been trained in High Voltage Awareness and have completed all required certification courses (if applicable) are permitted to perform this procedure. Proper personal protective equipment (PPE) and insulating HV gloves with a minimum rating of class 0 (1000V) must be worn at all times a high voltage cable, busbar, or fitting is handled. Refer to Tech Note TN-15-92-003, High Voltage Awareness Care Points for additional glove and safety information.
  • 2026-04-27: Released new procedure.
  1. Raise and support the vehicle. See Raise Vehicle - 2 Post Lift.
  2. Open the LH front door and lower the LH front window.
  3. Connect a laptop with toolbox 3 to the vehicle. See Toolbox 3 (Connect and Disconnect).
  4. Place the vehicle into Service Mode. See Service Mode.
  5. Unlock the vehicle Gateway. See Gateway (Unlock).
  6. Run ODIN routine PROC_HVBATT_X_DEVICE-CLUSTER-REPLACEMENT-BACKUPvia Service Mode Plus:High Voltage Battery ➜ Device Cluster Assembly (DCA) Replacement ➜ Backup Old DCAvia Toolbox:(link)
  7. Remove the tonneau slats. See Slat System - Tonneau (Remove and Install).
  8. Disconnect MV power. See Mid-Voltage Power (Disconnect and Connect) (Modify).
  9. Perform vehicle HV disablement procedure. See Vehicle HV Disablement Procedure (without Terrestrial Armor) (Test/Adjust).
  10. Remove pyro fuse access cover
    Note
    4x bolts, E-Torx 5 lobe, 10 Nm
  11. Remove primary pyro fuse
    Note
    2x bolts, 13mm, 5 Nm + 60 Degrees, Support pyro fuse while removing bolts
  12. Remove secondary pyro fuse
    Note
    2x bolts, 13mm, 5 Nm + 60 Degrees, Support pyro fuse while removing bolts
  13. Release connectors at 2x4 header (AC compressor and Inductive Charger headers)
    Note
    2x connectors, Fully release red lock tab, Pull black latch down to release connector
  14. Release 2x4 header assembly
    Note
    4x bolts, 5-lobe 10mm, 6 Nm
  15. Release drive unit connectors from ancillary headers
    Note
    3x connectors, Release blue lock tab, Rotate black latch
  16. Remove bolts securing HC-Stak HV Headers for LHRDU, FDU, RHRDU from ancillary flange
    Note
    6x bolts, 5-lobe 10mm, 10 Nm
  17. Remove LHRDU, FDU, RHRDU headers from ancillary flange
    Note
    3x headers, No tools required, inspect header seals, Replace header if damaged
  18. Lower vehicle until tires are touching the ground
    Note
    Raise lift off locks, then hold lock release lever to keep locks free while vehicle is lowered
  19. Remove the bed floor assembly. See Bed Floor Assembly (Long Range) (Remove and Install).
  20. Remove the NVH barrier. See Tonneau NVH Barrier Assembly (Remove and Install).
  21. Disconnect ancillary bay MV connector
    Note
    1x connector, Double locking, Release tab then pivot lever, Release second tab to disengage connector, Wait 1 second between locking tab release to discharge and prevent arcing
  22. Remove bolt securing busbar HV connector lid
    Note
    1x bolt, EP10, 9 Nm
  23. Remove bolts securing HV connector to DC FC header
    Note
    2x bolts, 10mm, 9 Nm
  24. Release HV connector from DC FC header
    Note
    1x connector, Use inflatable airbag if needed to suspend busbar assembly above ancillary assembly
  25. Support HV Busbar assembly
    Note
    1X Bungee, Suspend assembly to maintain clearance, wrap bungee around busbar assembly to achieve required cord length, Connect bungee to tie down hook on bed side
  26. Remove fast charger header doubler
    Note
    2x bolts, E10 5 Lobe Torx, 10 Nm
  27. Remove mid voltage header bolts
    Note
    2x bolts, EP10, 6 Nm
  28. Release fasteners securing ancillary bay cover to HV battery
    Note
    22x bolts, E10 5-Lobe, 6 Nm, Use E10 5-Lobe socket without magnet, The fasteners are captive and will stay attached to the penthouse cover, Follow fastening order
  29. Remove ancillary bay cover
    Note
    Install vacuum cup to ancillary bay cover surface, Lift and maneuver cover around busbar and tonneau cage to remove
  30. Inspect ACJB to PCS Harness
    Note
    Inspect harness part number, If REV is earlier than J then replace with REV J or later, If REV is J or later then proceed with current procedure
  31. Remove ACJB to PCS HV jumper harness
    Note
    2x connectors, Release locking tab and pull connector out of respective header, Do not pull on harness
  32. Release ACJB LV connector & ACJB to device cluster HV connector
    Note
    2x connectors, Release connector locks, Depress levers and pull at connectors, Do not pull at harness, inspect ACJB to DC HV harness part number, if not rev J or newer, replace harness
  33. Release ancillary bed outlet and dummy plug connectors
    Note
    1x connector,1x dummy plug Release locking tabs, Slide locks to release
  34. Release ACJB fasteners
    Note
    6x bolts, E10 5 Lobe Torx, 6Nm
  35. Release ACJB from ancillary tray
    Note
    2x clips, 2x datums, Release clips at headers, Slide ACJB inboard on datums
  36. Remove ACJB from ancillary tray
    Note
    Lift over and out of PCS once headers clear outboard side of ancillary tray
  37. Install ACJB onto ancillary tray
    Note
    Align headers and slide openings to datums in ancillary tray
  38. Slide ACJB into ancillary tray until header clips are fully engaged
    Note
    Ensure all fastener holes are aligned
  39. Secure ACJB fasteners
    Note
    6x bolts, E10 5 Lobe Torx, 6Nm
  40. Secure ancillary bed outlet connector and dummy plug to ancillary
    Note
    1x connector,1x dummy plug, Slide locks to fully engage, Secure locking tabs
  41. Install ACJB to PCS HV jumper harness
    Note
    2x connectors, Secure at ACJB first then fold harness over to PCS, Secure locking tab on both connectors
  42. Secure ACJB LV harness connector & ACJB HV harness to device cluster connector
    Note
    2x connectors, Secure connector locks
  43. Install ancillary cover
    Note
    Use suction cup and maneuver around busbar and tonneau cage
  44. Secure ancillary cover fasteners to HV battery
    Note
    22x bolts, E10 5-Lobe, 6 Nm, Use E10 5-Lobe socket without magnet, The fasteners are captive and will stay attached to the penthouse cover, Follow fastening order
  45. Install mid voltage header bolts
    Note
    2x bolts, EP10, 6 Nm
  46. Install fast charger header doubler
    Note
    2x bolts, E10 5 Lobe Torx, 10Nm
  47. Clean HV connector contact surface of residual Penetrox
    Note
    Allow 1 minute dry time after removing Penetrox, New busbar comes with Penetrox applied to HV connector
  48. Clean busbar HV connector contact surface of residual Penetrox
    Note
    Allow 1 minute dry time after removing Penetrox, It is necessary to clean HV connector during re-use of busbar
  49. Apply Penetrox onto HV connector joints
    Note
    Apply 2 drops of Penetrox A-13 about 5mm in diameter to either side of the hole on both leads, Spread evenly to verify the contact surface is fully covered
  50. Position busbar connector and lower onto HV header
    Note
    Release bungee cord
  51. Install bolts securing charge port busbar kit to HV Header
    Note
    2x bolts, 10mm, 9 Nm
  52. Perform Hioki resistance test at each HV joint from HV busbar lead to bolt head
    Note
    2x HV joints, When using Hioki tester, verify the meter has been properly adjusted and set prior to usageThe acceptable resistance is between 0.050 mΩ (50 μΩ) and 0.195 mΩ (195 μΩ).If the resistance is greater than 0.195 mΩ (195 μΩ), stop work and escalate the Toolbox session.If the resistance is lower than 0.050 mΩ (50 μΩ), reposition the probes and measure again.If the resistance is repeatedly between 0.00 mΩ and 0.050 mΩ (50 μΩ), hioki test passed, proceed to next step
  53. Install bolt securing busbar HV connector lid
    Note
    1x bolt, EP10, 9 Nm
  54. Remove leather over gloves and HV insulating gloves
  55. Connect ancillary bay MV connector
    Note
    1x connector, double locking, Rotate lever into 2nd lock, Perform a pull test to ensure connector engaged correctly
  56. Raise vehicle fully and lower lift onto locks
    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
  57. Inspect HV insulating gloves
    Note
    Check gloves for damage prior to use, Refer to service document TN-15-92-003, for information on inspecting HV gloves.
  58. Put on HV insulating gloves and leather over gloves
  59. Install LHRDU, FDU, RHRDU headers to ancillary flange
    Note
    3x headers, No tools required, inspect header seals, Replace header if damaged
  60. Secure bolts to HC-Stak HV Headers for LHRDU, FDU, RHRDU to ancillary flange
    Note
    6x bolts, 5-lobe 10mm, 10 Nm
  61. Secure 2x4 header assembly
    Note
    4x bolts, 5-lobe 10mm, 6 Nm, Confirm alignment of assembly with fastener openings
  62. Secure connectors at 2x4 header (AC compressor and Inductive Charger headers)
    Note
    2x connectors, Fully engage red lock tab
  63. Secure drive unit connectors to ancillary headers
    Note
    3x connectors, Rotate black latch, Ensure blue locking tab is fully engaged
  64. Install secondary pyro fuse
    Note
    2x bolts, 13mm, 5 Nm + 60 degrees, Support pyro fuse while installing bolts, Bolts may be reused
  65. Install primary pyro fuse
    Note
    2x bolts, 13mm, 5 Nm + 60 degrees, Support pyro fuse while installing bolts, Bolts may be reused
  66. Perform Hioki resistance test at each HV joint from HV busbar lead to pyro fuse busbar
    Note
    4x HV joints, When using Hioki tester, verify the meter has been properly adjusted and set prior to usageThe acceptable resistance is between 0.050 mΩ (50 μΩ) and 0.195 mΩ (195 μΩ).If the resistance is greater than 0.195 mΩ (195 μΩ), stop work and escalate the Toolbox session.If the resistance is lower than 0.050 mΩ (50 μΩ), reposition the probes and measure again.If the resistance is repeatedly between 0.00 mΩ and 0.050 mΩ (50 μΩ), hioki test passed, proceed to next step
  67. Install pyro fuse access cover with airlines attached
    Note
    4x bolts, E-Torx 5 lobe, 10 Nm, Ensure seal is fully seated and undamaged, Secure 2 airline mounting clips to HV Battery, If HV pack is being shipped then pyro fuses must be removed
  68. Remove leather over gloves and HV insulating gloves
  69. Install the rear skid plate. See Skid Plate - Rear (Remove and Install).
  70. Lower vehicle until tires are touching the ground
    Note
    Raise lift off locks, then hold lock release lever to keep locks free while vehicle is lowered
  71. Reconnect MV power. See Mid-Voltage Power (Disconnect and Connect) (Modify).
  72. Install the rear underhood apron. See Underhood Apron - Rear (Remove and Install).
  73. Install the NVH barrier. See Tonneau NVH Barrier Assembly (Remove and Install).
  74. Install the bed floor assembly. See Bed Floor Assembly (Long Range) (Remove and Install).
  75. Install the tonneau slats. See Slat System - Tonneau (Remove and Install).
  76. Exit Service Mode. See Service Mode.
  77. Raise the LH front window and close the LH front door.
  78. Remove the vehicle from the lift. See Raise Vehicle - 2 Post Lift.