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Hybrid Service Disable Procedures Cadillac Escalade GMT900

Body Electrical 1 illustration ~1482 words

SAFETY PRECAUTIONS

WARNINGAlways perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed. The High Voltage Disabling procedure will perform the following tasks: Identify how to disable high voltage. Identify how to test for the presence of high voltage. Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed. Failure to follow the procedures exactly as written may result in serious injury or death.
WARNINGEnsure all High Voltage safety procedures are followed. Failure to follow the procedure exactly as written may result in serious injury or death.
WARNINGBefore working on any high voltage system, be sure to wear the following Personal Protection Equipment: Safety glasses with appropriate side shields when within 50 feet of the vehicle, either indoors or outdoors Certified and up-to-date Class "0" Insulation gloves rated at 1000V with leather protectors Visually and functionally inspect the gloves before use. Wear the Insulation gloves at all times when working with the high voltage battery assembly, whether the system is energized or not. Failure to follow the procedure exactly as written may result in serious injury or death.
WARNINGThis vehicle is equipped with a high voltage battery that is completely isolated from the chassis ground. Never utilize AC powered test equipment to probe the high voltage system. Serious injury, death and component damage could occur if the high voltage system is grounded through the electric utility. Failure to follow the procedure exactly as written may result in serious injury or death.

Precautions when Performing Service or Inspections

  1. Always verify that the high voltage has been disabled before working on or around high voltage components, wires, cables, or harnesses.
  2. Remove all metal objects such as rings and watches.
  3. The EL-48900 HEV Safety Kit contains safety cones. Place the safety cones around the vehicle to alert other technicians that you are working on the High Voltage system.
  4. Attach the ignition key to the high voltage manual disconnect lever and put the lever and the ignition key in a secure place.
  5. Always wear certified and tested high voltage insulation gloves when inspecting or testing any high voltage wires and components.
  6. Use the "One Hand" rule: Work with only one hand whenever possible. Keep the other hand behind your back.
  7. DO NOT carry any metal objects such as a mechanical pencil or a measuring tape that could fall and cause a short circuit.
  8. After removing any high voltage wires, protect and insulate the terminal ends immediately with the EL-48569 terminal covers and UL® Listed or equivalent insulation tape rated at a minimum of 600 volts. See Special Tools .
  9. Always tighten the high voltage terminal fasteners to the specified torque. Insufficient or excessive torque will cause malfunctions or damage.
  10. After finishing work on the high voltage systems and before reinstalling the high voltage manual disconnect lever, inspect for the following: Verify high voltage system integrity and that all connectors are installed. Verify that all tools or loose components have been removed.

Labels for Components, Wire Harness, and Connectors: The wire harnesses and cables for high voltage circuits are encased in an orange colored covering. In addition, high voltage components such as the Energy Storage System and high voltage cables are affixed with "High Voltage" red danger (1) and orange warning (2) labels. The intermediate 42 volt system is encased in a blue colored covering, and has yellow caution (3) labels on the components, wire harnesses, and cables. (Scheme 1)

Scheme 1

Scheme 1
Scheme 1

High Voltage insulation Glove Inspection Procedure

The following procedure visually and functionally inspects the insulation gloves to be used while performing service on high voltage systems. This inspection procedure should be performed prior to any procedure that requires the use of class "0" insulation gloves rated at 1000 volts.

  1. Remove glove from leather protector.
  2. Inflate glove and seal opening. Pinch the opening closed tightly to prevent any air loss.
  3. Press glove to increase pressure.
  4. Inspect for the following conditions: pin holes air leaks wear, tears, or abrasions damp or wet material certified up-to-date If any of the above conditions are met, do not use the gloves.

SPECIAL TOOLS

  1. EL-48569 Terminal Covers.
  2. EL-48900 HEV Safety Kit

DISCONNECT

  1. Review the «SAFETY PRECAUTIONS»(/cadillac/escalade/gmt900-2006-2014/remont/body-electrical/#hybrid-service-disable-procedures__safety-precautions) prior to performing the High Voltage Disabling procedure.
  2. Disable the voltage sources to the 2 mode hybrid vehicle. Remove the ignition key. Remove the rear seat frame front finish cover. see scheme 2 Remove the high voltage manual disconnect lever. Attach the ignition key to the lever and put the lever and the ignition key in a secure place. see scheme 3 Wait 5 minutes before continuing, to allow the capacitors to discharge.

ISOLATION CHECK

IMPORTANTUse the correct procedure, depending on components being serviced. When Servicing Drive Motor Generator Battery Assembly or 300 V DC Cable When Servicing Drive Motor Generator Control Module Assembly or Cable Connections
IMPORTANTThe 12-volt battery must be disconnected to ensure proper test results.

ISOLATION CHECK: WHEN SERVICING DRIVE MOTOR GENERATOR BATTERY ASSEMBLY OR 300 V DC CABLES

  1. Disconnect the 12-volt battery.
  2. Remove the rear seat riser finish cover.
  3. Remove the terminal extension cover assembly. see scheme 4
  4. To verify that the voltage has been disabled at the drive motor generator battery assembly terminals, perform the following: Set the digital multimeter (DMM) to DC mode. Verify the DMM works by measuring the voltage of the 12-volt battery. Using the DMM, verify the voltage measures less than 3V at the following points: Across the HVDC (+) positive (3) and HVDC (-) negative (4) terminals. see scheme 5 If the test result was greater than 3 V, the drive motor generator control module internal capacitors are still charged. Keep the insulation gloves on and install the cable cover. Wait 5 minutes and then remove the cover and return to the beginning of this step. HVDC (+) positive (3) to vehicle chassis ground. see scheme 5 HVDC (-) negative (4) to vehicle chassis ground. see scheme 5 If the test result was greater than 3V, there is a stuck closed contactor and a loss of isolation within the drive motor generator battery assembly.
  5. Using a DMM test for voltage from the High Voltage manual disconnect terminal (1) to the High Voltage DC positive and negative terminal connections (3, 4). see scheme 5 The result should be less than 3V. If the test result was greater than 3V, a high voltage positive contactor relay or the precharge relay is stuck closed.
  6. Using a DMM test for voltage from the High Voltage manual disconnect terminal (2) to the high voltage DC positive and negative terminal connections (3, 4). see scheme 5 The result should be less than 3V. If the test result was greater than 3V, the high voltage negative contactor relay is stuck closed.
  7. Retest the DMM by measuring the 12-volt battery. If the DMM does not properly measure the 12-volt battery, repair or replace the DMM and repeat all voltage measurements. If all the test results were less than 3V, the 300V DC cables can now be removed from the drive motor generator battery assembly.

ISOLATION CHECK: WHEN SERVICING DRIVE MOTOR GENERATOR CONTROL MODULE ASSEMBLY OR CABLE CONNECTIONS

  1. Disable the voltage sources to the 2 mode hybrid vehicle. Remove the ignition key. Remove the rear seat frame front finish cover. Remove the high voltage manual disconnect lever. Attach the ignition key to the lever and put the lever and the ignition key in a secure place. Wait 5 minutes before continuing, to allow the capacitors to discharge.
  2. Disconnect the 12-volt battery
  3. Remove the drive motor generator control module sight shield.
  4. Remove the 3-phase cable cover.
  5. To verify that no voltage is present at the high voltage connection for the drive motor generator control module, perform the following: Set the digital multimeter (DMM) to DC mode. Verify the DMM works by measuring the voltage of the 12-volt battery. Using the DMM, verify the voltage measures less than 3V at the following points: HVDC (+) positive (1) and HVDC (-) negative (2) terminals. see scheme 7 If the test result was greater than 3V, the drive motor generator control module internal capacitors are still charged. Keep the insulation gloves on and install the 3-phase cable cover. Wait 5 minutes and then remove the 3 phase cable cover and return to the beginning of this step. HVDC (+) positive (1) to vehicle chassis ground. see scheme 7 HVDC (-) negative (2) to vehicle chassis ground. see scheme 7 If the test result was greater than 3V, there is a stuck closed contactor and a loss of isolation within the drive motor generator battery assembly.
  6. Retest the DMM by measuring the 12-volt battery. If the DMM does not properly measure the 12-volt battery, repair or replace the DMM and repeat all voltage measurements. If all the test results were less than 3V, the cables can now be removed from the drive motor generator control module assembly.

CONNECT

WARNINGEnsure all High Voltage safety procedures are followed. Failure to follow the procedure exactly as written may result in serious injury or death.
WARNINGBefore working on any high voltage system, be sure to wear the following Personal Protection Equipment: Safety glasses with appropriate side shields when within 50 feet of the vehicle, either indoors or outdoors Certified and up-to-date Class "0" Insulation gloves rated at 1000V with leather protectors Visually and functionally inspect the gloves before use. Wear the Insulation gloves at all times when working with the high voltage battery assembly, whether the system is energized or not. Failure to follow the procedure exactly as written may result in serious injury or death. Review the SAFETY PRECAUTIONS prior to performing the High Voltage Enabling procedure.
  1. Ensure that the 12-volt battery is disconnected.
  2. After finishing work on the high voltage systems and before reinstalling the high voltage manual disconnect lever, inspect for the following: Verify that all tools or loose components have been removed. Verify high voltage system integrity and that all connectors are installed. Verify that all high voltage interlock circuit (HVIC) connectors and covers are installed.
  3. Install the high voltage manual disconnect lever. see scheme 3
  4. Install the rear seat riser finish cover.
  5. Connect the 12-volt battery.
  6. Start the engine, then turn the ignition OFF.
  7. Ignition ON, clear all DTC Information with a scan tool.
  8. Ignition OFF, wait 2 minutes.
  9. Ignition ON, verify with a scan tool no DTCs are set. If DTCs are set go to appropriate DTC information.
  10. Verify that High Voltage has enabled by observing the HPCM 300 V Circuit voltage scan tool parameter. If High Voltage is not enabled and no DTCs are set, return to Step 6.
  11. Start and idle the engine for 2 minutes.
  12. Ignition OFF wait 5 minutes.
  13. Ignition ON, verify with the scan tool HPCM DTC Information that the following DTCs have Ran Since Code Clear and have not set: Contactor relay DTCs P0ADC, P0AE7 and P0AE0 Discharge and Pre-charge DTCs P0C76, P0C77, and P1A20 Motor position sensor learn DTCs P0C17 and P0C18 High voltage loss of isolation DTCs P1AE7, P1AF0 and P1AF2.
  1. If the DTCs have Ran and Passed, test drive the vehicle and verify no DTCs are set.
  2. If the DTCs are set, go to the appropriate DTC information.
  3. If the DTCs have Not Ran Since Code Clear, review and operate the vehicle according to the applicable DTC Conditions for Running and ensure the DTCs run and pass.

See also:
• SAFETY PRECAUTIONS

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