Circuit/System Testing
Always 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 includes the following steps:
- 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.
Before working on any high voltage system, be sure to wear the following Personal Protection Equipment:
- Safety glasses with appropriate side shields when within 15 meters (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 with leather protectors at all times when working with the high voltage battery assembly, whether the system is energized or not.
Failure to follow the procedures may result in serious injury or death.
- Vehicle OFF, disable high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling
- Remove the A4 hybrid/EV battery pack cover. Refer to High Voltage Battery Cover Replacement
- Disconnect the harness connector to the K112 Hybrid/EV Battery Interface Control Module at the appropriate C4 Hybrid/EV Battery Section as indicated by the voltages observed during Circuit/System Verification.
- Inspect the harness connector and the appropriate C4 Hybrid/EV Battery Section connector for corrosion.
- If corrosion is present
Replace the Hybrid/EV Battery Pack Internal Harness and the C4 Hybrid/EV Battery Section, as applicable.
- Go to next step: If corrosion is not present
- If corrosion is present
- Connect the EL-48571 High Voltage Battery Pin Out Box with the EL-48571-45 Battery Pinout Box Adapter to the appropriate battery section.
- Insert the DMM probes into the EL-48571 test cavities.
- Measure and record the voltage of each of the cell groups by cycling the EL-48571 through each of the switch positions. Refer to EL-48571 High Voltage Battery Pin Out Box Reference
- Verify each cell group voltage reading is between 1.60 - 4.50V.
- If not within the specified range
Replace the appropriate C4 Hybrid/EV Battery Section.
- Go to next step: If within the specified range
- If not within the specified range
- Verify each cell group voltage reading is within 0.03V of each other.
- If greater than 0.03V
Replace the appropriate C4 hybrid/EV battery section.
- Go to next step: If 0.03V or less
- If greater than 0.03V
- Replace the appropriate K112 Hybrid/EV Battery Interface Control Module.
If a service replacement battery section is required, the replacement battery section will need to have its cell voltages balanced (matched) to the remaining battery sections with the EL-50332 Hybrid/EV Battery Service Tool. The EL-50332 connects to the replacement section(s) via alligator clamps. To facilitate connection of the alligator clamps, always install a replacement section into the C4D Hybrid/EV Battery Section 4 or C4E Hybrid/EV Battery Section 5 location. Reposition the existing C4D or C4E battery section into the location of the battery section requiring replacement as applicable.
The Hybrid/EV Battery Section Wiring Schematic in Energy Storage identify the battery section and voltage sense circuit terminal locations appropriate to each cell group and corresponding DTC.