Depower a hybrid vehicle and test high-voltage battery health

You are a technician completing your high-voltage authorisation in the hybrid and electric vehicle bay.

Simulated workplaceAdvanced missionCAQA Torque Automotive

What is going on

Stock vehicle U2318, a 2023 hybrid SUV taken as a trade-in, needs a high-voltage battery state of health test and an inverter coolant service before Vehicle Sales can list it, on repair order RO-26-4497. The master technician will observe you plan and carry out the depower as part of your authorisation. A week ago an apprentice walked inside the EV bay barrier while a vehicle was depowered, so the Service Manager has made the barrier, signage and service plug control non-negotiable. The insulated gloves must be within their six-month test date, which is recorded in the Plant and Equipment Register. The vehicle must be reinitialised, checked and the result recorded before the pre-delivery checklist can be completed.

Bree Kowalski, Master Technician, Hybrid and Electric Vehicles
Subject: Depower and battery health test on stock U2318

The silver hybrid SUV, stock U2318, needs a high-voltage battery state of health test before sales can list it, and the inverter coolant is due. I want you to plan and carry out the depower with me watching. Read the Hazardous Substances and High Voltage Isolation Procedure, check the glove test dates in the Plant and Equipment Register, set up the bay and record the zero voltage check on RO-26-4497. After last week's near miss the barrier and signage are non-negotiable.

Your brief

Plan and carry out the depower in the manufacturer sequence, verify zero voltage, complete the battery state of health test and coolant service, reinitialise the vehicle, and record every step on the repair order and the pre-delivery checklist.

Work through it

You do not need to do it all. Doing a few of these will show you what the work is like. Your ticks and notes stay on this device.

Read the Hazardous Substances and High Voltage Isolation Procedure and the manufacturer depower sequence, then write a short job plan listing the steps, equipment and personal protective equipment.
Check the Plant and Equipment Register for the insulated glove test date and the meter calibration, and inspect the gloves for damage before use.
Move the vehicle to the isolated bay, set up the barrier, warning sign, rescue hook and insulated mat, and brief anyone working nearby.
Depower the vehicle in the manufacturer sequence, secure the service plug on your person or in the locked box, wait the discharge period and verify zero voltage with the rated meter.
Record the zero voltage reading, time and witness on RO-26-4497 in the Repair Orders system.
Carry out the battery state of health test and the inverter coolant service, recording results and quantities on the repair order.
Reinitialise the vehicle in the manufacturer sequence, confirm no fault codes and complete the pre-delivery checklist items that relate to the high-voltage system.
Update the Vehicle Stock Register note for U2318 with the battery health result so Vehicle Sales can proceed.

My notes: what did I enjoy, and what surprised me?

What someone in this role would produce

Written job plan for the depower
Repair order showing zero voltage verification, test results and reinitialisation
Plant and Equipment Register check of gloves and meter
Updated Vehicle Stock Register note for U2318

Printing this is a record of what you explored. It is not a certificate or a qualification.