High Voltage Cable Inspection

Comprehensive inspection of all high-voltage cables, connectors, and insulation on the 65 kWh battery system to identify damage, corrosion, or wear that could cause electrical faults or safety hazards.

Warnings

Tools required

Parts

• High-voltage warning labels (if damaged) × 1 — GM 84178187
• High-voltage connector seals (if damaged) × 1 — Use OEM specification
• Orange conduit protective wrap (if abraded) × 1 — GM HV cable protection kit
• Dielectric grease for HV connectors × 1 — GM 12345579 or equivalent

Preparation

1. Park vehicle on level surface and engage parking brake. Ensure vehicle is in Park mode.
2. Verify you have proper high-voltage safety training certification and appropriate personal protective equipment.
3. Ensure a second qualified person is present for safety monitoring.
4. Turn vehicle OFF using power button and remove key fob from vehicle (minimum 15 feet away).
5. Open hood and locate 12V battery in front compartment. Disconnect negative terminal and wait 2 minutes for vehicle systems to power down.
6. Place 'HIGH VOLTAGE WORK IN PROGRESS' warning signs on windshield and at work area.
7. Connect scan tool and verify no high-voltage system DTCs present. Clear any unrelated codes and document initial state.
8. Review vehicle service history for any previous high-voltage system work or collision repairs.

Procedure

1. 1

   Remove Service Disconnect and Verify De-energization
   Remove rear seat bottom cushion by pulling up firmly at front edge. Locate orange service disconnect cover on battery pack (center-rear of battery assembly). Remove cover by turning counterclockwise. Wearing insulated gloves, pull service disconnect handle straight up to extract disconnect plug. Install lockout device on service disconnect to prevent re-insertion. Wait minimum 5 minutes for high-voltage system capacitors to discharge. Place service disconnect in secure location away from vehicle.
   ⚠️Do not touch any high-voltage components during the 5-minute waiting period. Capacitors retain lethal voltage.
2. 2

   Verify Zero Voltage at Battery Pack
   Set multimeter to DC voltage (minimum 600V scale). Wearing insulated gloves and face shield, access the main battery terminals visible through the service disconnect opening. Carefully measure voltage between positive and negative battery busbars. Verify reading is 0V DC (less than 3V is acceptable residual). Also measure from each busbar to vehicle chassis ground - both should read 0V. If any reading exceeds 3V, wait additional 5 minutes and re-test. Document all voltage readings.
   ⚠️If voltage does not drop below 3V after 10 minutes total wait time, DO NOT PROCEED. System fault is present - contact GM technical assistance.
3. 3

   Remove Underbody Covers for Cable Access
   Raise vehicle on lift to comfortable working height. Remove front underbody shield (10 plastic clips and 4 bolts). Remove battery pack underbody cover (multiple screws around perimeter). Remove rear underbody shield sections as needed for full cable routing visibility. Label and organize all fasteners by location for reinstallation.
   Torque spec

   Cover Screws11 Nm (8 lb-ft)
4. 4

   Inspect Battery to Drive Unit High-Voltage Cable
   Locate main high-voltage cable running from battery pack (rear) to drive unit (front). This is a thick orange cable approximately 25mm diameter. Inspect entire cable length for: cuts, abrasions, or damage to orange outer insulation; deformation, crushing, or flat spots; exposure of underlying shielding or conductors; signs of heat damage (discoloration, melting); proper routing through protective conduit; adequate clearance from sharp edges, exhaust components, and moving parts (minimum 25mm clearance required). Check all cable securing clips and brackets for damage or looseness. Use mirror to inspect upper cable routing near frame rails.
   ⚠Even minor damage to orange insulation compromises high-voltage safety. Any insulation damage requires complete cable assembly replacement.
5. 5

   Inspect Battery Pack High-Voltage Connectors
   Locate high-voltage connectors at battery pack (typically 2-4 connector locations on pack top/sides). Inspect each connector for: orange safety lock engaged properly; connector housing cracks or damage; corrosion on visible terminals; moisture intrusion or water staining; proper seating with no gaps between connector halves; security of connector mounting brackets. Check connector bolt torque without loosening - should be firm. Inspect orange protective boots for tears or deterioration.
   ⚠Do not disconnect high-voltage connectors unless specific damage is found requiring further inspection. Each disconnection risks seal and terminal damage.
   Torque spec

   Connector Bolts7 Nm (5 lb-ft)
6. 6

   Inspect Drive Unit High-Voltage Connectors
   At front of vehicle, locate high-voltage cable connections to drive unit (motor/inverter assembly). Inspect drive unit high-voltage connectors using same criteria as battery connectors: housing integrity, orange lock engagement, seal condition, terminal corrosion, and proper seating. Check for evidence of arcing (carbon deposits, melted plastic, or unusual discoloration around terminals). Verify connector mounting bolts are present and secure.
   Torque spec

   Connector Bolts7 Nm (5 lb-ft)
7. 7

   Inspect Charge Port to Battery High-Voltage Cable
   Locate charge port high-voltage cables running from left front charge port to battery pack. These may be two separate cables (AC and DC charging). Trace entire cable routing checking for: proper conduit protection throughout length; secure mounting at all bracket points; damage from road debris (especially near front of vehicle); proper grommet sealing where cables enter battery pack; adequate clearance from suspension components during full suspension travel. Open charge port door and inspect connections at charge port controller for corrosion or damage.
   Torque spec

   Bracket Bolts20 Nm (15 lb-ft)
8. 8

   Inspect Auxiliary High-Voltage Cables
   Inspect additional high-voltage cables including: battery heater cables (if equipped), battery cooling system power cables, and high-voltage junction box connections. Verify all orange-coded cables have proper strain relief, are routed away from heat sources, and have no sharp bends (minimum bend radius 150mm for HV cables). Check all cable ties and securing straps are intact and not over-tightened (should not compress cable diameter).
   ℹ️Cable ties should secure cables firmly but not deform the round cable profile. Replace any damaged or over-tightened cable ties.
9. 9

   Measure Insulation Resistance (Megohm Test)
   Using high-voltage multimeter in insulation resistance mode (megohm setting), verify isolation between high-voltage system and vehicle chassis. With service disconnect still removed, measure resistance from positive busbar to chassis ground - should exceed 100 megohms. Measure negative busbar to chassis ground - should exceed 100 megohms. Measure between positive and negative busbars - should show continuity through disconnect interlock circuit (typically 500-2000 ohms). Record all measurements. Values below specification indicate insulation breakdown or moisture intrusion.
   ⚠Insulation resistance below 100 megohms to ground indicates serious fault. Do not return vehicle to service - locate and repair fault before proceeding.
10. 10

    Inspect High-Voltage Interlock Loop
    Verify high-voltage interlock loop (HVIL) circuit integrity. This low-voltage safety circuit runs through all HV connectors. Inspect orange HVIL wire running alongside main HV cables. Check for: wire continuity and proper routing; connector pins clean and not corroded; no damage to HVIL wire insulation; proper connection at service disconnect location. Use multimeter to verify HVIL circuit resistance (typically 240-360 ohms with all connectors seated and service disconnect removed).
    ℹ️HVIL circuit prevents HV system energization if any HV connector is unseated. Open HVIL circuit will set DTC and prevent vehicle operation.
11. 11

    Check Cable Securing Brackets and Routing
    Inspect all high-voltage cable mounting brackets and supports. Verify bracket bolts are tight and brackets are not cracked or deformed. Confirm cables cannot contact: frame rails or sharp edges, exhaust system components (maintain 75mm minimum clearance), suspension components during full articulation, steering components during full lock-to-lock rotation. Check that cable protective conduit is continuous with no gaps exposing orange cable. Verify all cable pass-throughs have proper grommets installed.
    Torque spec

    Bracket Bolts20 Nm (15 lb-ft)

    Module Mounting Bolts8 Nm (6 lb-ft)
12. 12

    Inspect High-Voltage Warning Labels
    Verify all high-voltage warning labels are present, legible, and properly adhered. Required label locations include: battery pack top cover, drive unit assembly, charge port area, service disconnect cover, and high-voltage junction boxes. Replace any damaged, missing, or illegible warning labels. Labels must be fluorescent orange with black text and lightning bolt symbol clearly visible.
    ⚠Warning labels are critical safety devices. Missing or illegible labels must be replaced before returning vehicle to service.
13. 13

    Perform Connector Detail Inspection (If Issues Found)
    If previous inspection revealed connector issues, perform detailed connector inspection: Wearing insulated gloves, unlock orange safety lock on affected connector. Carefully separate connector halves noting any resistance (should separate smoothly). Inspect terminal pins for: corrosion, discoloration from heat, proper retention in housing, damage or deformation. Inspect connector seals for compression set, tears, or displacement. Check connector housing for cracks using magnification. If cleaning needed, use only dry compressed air or approved non-conductive contact cleaner. Apply fresh dielectric grease to terminals if connector was separated. Reconnect and verify positive locking engagement.
    ⚠️Only disconnect HV connectors if specific defect requires it. Each connection/disconnection risks terminal and seal damage.
    Torque spec

    Connector Bolts7 Nm (5 lb-ft)
14. 14

    Document Findings and Prepare Service Report
    Create comprehensive inspection report documenting: all voltage measurements taken; insulation resistance test results; condition of each HV cable section with mileage locations of any damage; condition of all HV connectors with photographs; HVIL circuit test results; any warning labels replaced; any cables, brackets, or components requiring replacement. For any damage found, note severity and whether immediate replacement is required or monitoring is acceptable. Update vehicle service records with inspection completion and findings.
    ℹ️Any high-voltage cable damage requiring replacement is a critical safety issue. Vehicle should not be returned to customer until repairs are completed.

Reassembly

1. If any connectors were separated during inspection, reconnect and torque High-Voltage Connector Bolts to specification ensuring orange safety locks fully engage.
2. Reinstall all underbody covers and shields, torquing Cover Screws and Mounting Bolts to specification.
3. Reinstall all cable brackets and supports torquing Bracket Bolts to specification.
4. Verify all high-voltage cables are properly routed through protective conduit with adequate clearance from all components.
5. Before reinstalling service disconnect, perform final visual inspection of all high-voltage components to ensure no tools or parts are left in battery area.
6. Wearing insulated gloves, reinstall service disconnect plug by inserting straight down until fully seated with positive click. Remove lockout device.
7. Install service disconnect cover and rotate clockwise to lock. Reinstall rear seat cushion.
8. Reconnect 12V battery negative terminal and torque to 11 Nm (8 lb-ft).

Verification

• Connect scan tool and clear any DTCs that may have set during service disconnect removal.
• Start vehicle and verify Ready indicator illuminates and no warning messages appear on driver information center.
• Verify no high-voltage DTCs present using scan tool. Specifically check for: P0AFA (HV system isolation fault), P0AA6 (HV system interlock fault), and any HV battery or drive unit codes.
• Perform test drive including gentle acceleration, regenerative braking, and full-power acceleration to verify normal high-voltage system operation.
• After test drive, perform final underbody visual inspection to verify no cables loosened or shifted during vehicle operation.
• Re-measure insulation resistance from HV system to ground - should still exceed 100 megohms with vehicle in Ready mode (service disconnect installed).
• Document final verification results in service records including post-repair scan tool data.
• Provide customer with written summary of inspection findings and any components requiring future monitoring or replacement.

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