AURETH004
Diagnose and repair traction motor speed control systems in battery electric vehicles


Application

This unit describes the performance outcomes required to diagnose and repair faults in the traction motor speed control systems in battery electric vehicles (BEVs). These systems may be referred to as digital motor controllers (DMCs) or motor control units (MCUs). The unit involves preparing for the task, selecting the correct diagnostic procedure, carrying out the diagnosis and the repair, performing post-repair testing, and completing workplace processes and documentation. Importance is placed in the unit on applying electrical safety procedures when working on high voltage (HV) rechargeable energy storage systems (RESS).

It applies to those working in the automotive service and repair industry. Motor speed control systems include circuits in BEVs.

No licensing, legislative, regulatory or certification requirements apply to this unit at the time of publication.


Elements and Performance Criteria

Elements

Elements describe the essential outcomes.

Performance Criteria

Performance criteria describe the performance needed to demonstrate achievement of the element. Where bold and italicised text is used, further information is detailed in the range of conditions section.

1. Prepare to diagnose and repair traction motor speed control systems

1.1 Job requirements are determined from workplace instructions

1.2 Diagnostic information is sourced and interpreted

1.3 Diagnostic options are analysed and those most appropriate to the circumstances are selected

1.4 Hazards associated with the work are identified and risks are managed according to safety requirements and AS 5732 Electric vehicle operations: Maintenance and repair

1.5 Diagnostic tools and equipment are selected and checked for serviceability

2. Diagnose motor speed control system

2.1 Diagnostic tests are carried out according to manufacturer specifications, workplace procedures andsafety requirements

2.2 Faults are identified from diagnostic test results and causes of faults are determined

2.3 Diagnosis findings and recommendations for necessary repairs or adjustments are reported according to workplace procedures

3. Repair motor speed control system

3.1 Repair information is sourced and interpreted

3.2 Repair options are analysed and those most appropriate to the circumstances are selected

3.3 Repair tools, equipment and materials are selected and checked

3.4 RESS service plug or manual service disconnect is located and isolated to depower vehicle HV RESS according to manufacturer specifications

3.5 Motor control systems and components are replaced, repaired or adjusted as required according to manufacturer specifications, workplace procedures, safety and environmental requirements, and without causing damage to components or systems

3.6 RESS service plug or manual service disconnect is reconnected and vehicle is reactivated

3.7 Post-repair testing is carried out according to workplace procedures to confirm fault rectification, and any further problems detected as having been introduced during the repair process are rectified

4. Complete work processes

4.1 Final inspection is made to ensure work is to workplace expectations and vehicle is presented ready for use

4.2 Work area is cleaned, waste and non-recyclable materials are disposed of, and recyclable material is collected

4.3 Tools and equipment are checked and stored and faulty electrical equipment is identified, tagged and isolated according to workplace procedures

4.4 Workplace documentation is processed according to workplace procedures

Evidence of Performance

Before competency can be determined, individuals must demonstrate they can perform the following according to the standard defined in the unit’s elements and performance criteria, range of conditions and foundation skills:

diagnose and repair traction motor speed control systems and associated components on two different battery electric vehicles (BEVs) to correct performance deficiencies.


Evidence of Knowledge

Individuals must be able to demonstrate knowledge of:

work health and safety (WHS) and occupational health and safety (OHS) requirements relating to diagnosing and repairing traction motor speed control systems in BEVs, including procedures for:

identifying hazards and controlling risks associated with:

working with high voltages in BEV electrical systems

wearing jewellery while working around high electrical currents

determining appropriate procedures for minimising risk associated with hazards, including applying electrical safety precautions:

using personal protective equipment (PPE), including electrical safety gloves with 1000 volt rating and high voltage (HV) insulating mat with Australian standards rating

identifying and using fire safety equipment as appropriate

using the ‘one hand rule’

following live system warning tags and signs

depowering the vehicle

isolating the HV rechargeable energy storage system (RESS) electrical supply

stabilising the vehicle electrical system

environmental requirements, including procedures for trapping, storing and disposing of waste released from traction motor speed control systems

key requirements of AS 5732 Electric vehicle operations: Maintenance and repair

operating principles of HV BEVs and associated components, including:

types of batteries

types of traction motors, including alternating current and direct current

types of motor controllers

battery charging

application, purpose and operation of traction motor speed control systems and components, including:

controller inputs

resolvers

controller outputs

battery interface

diagnostic testing procedures for battery electric vehicle systems, including:

accessing and interpreting scan tool system data, including:

diagnostic trouble codes (DTCs)

live data

freeze frame data

waveforms

using diagnostic flow charts

testing electrical systems, including:

accessing electrical terminals and using test probes without damaging connectors, fuse holders or wiring

controller input and output signals and waveforms

vehicle dynamic and static testing procedures

abnormal noise analysis

component failure analysis

testing motor speed controller cooling system

repair procedures for traction motor speed control systems, including:

tightening connections

replacing faulty or damaged cable connections

removing and replacing faulty or damaged components

removing and replacing motor speed controller

post-repair testing procedures for BEVs, including:

DTC clearing procedures

checking for electrical connector mating

static and dynamic performance tests of traction motors.


Assessment Conditions

Assessors must satisfy NVR/AQTF assessor requirements.

Competency is to be assessed in the workplace or a simulated environment that accurately reflects performance in a real workplace setting.

Assessment must include direct observation of tasks.

Where assessment of competency includes third-party evidence, individuals must provide evidence that links them to the BEV traction motor speed control systems that they have worked on, e.g. repair orders.

Assessors must verify performance evidence through questioning on skills and knowledge to ensure correct interpretation and application.

The following resources must be made available:

automotive repair workplace or simulated workplace

PPE and safety equipment, including electrical safety gloves with 1000 volt rating and HV insulating mat with Australian standards rating

manufacturer specifications for BEV traction motor speed control systems

AS 5732 Electric vehicle operations: Maintenance and repair

two different BEVs with traction motor speed control systems accessible for diagnosis and repair or replacement activities

electrical diagnostic equipment appropriate to the BEV being diagnosed and repaired, including:

digital multimeter with Cat III 1000 volt rating

insulation tester

scan tool

oscilloscope

residual voltage tester, if specified in original equipment manufacturer (OEM) test requirements

tools, equipment and materials appropriate for repairing high voltage traction motors in BEVs.


Foundation Skills

This section describes those language, literacy, numeracy and employment skills that are essential to performance and are not explicit in the performance criteria.

Skills

Description

Learning skills to:

identify and locate various sources of information efficiently.

Reading skills to:

interpret text, symbols and wiring diagrams in diagnostic and repair information in manufacturer specifications and workplace instructions and procedures.

Writing skills to:

legibly and accurately fill out workplace documentation when reporting diagnostic findings, making repair recommendations, and recording parts and material used.

Oral communication skills to:

clarify instructions

report diagnostic findings and make repair recommendations.

Numeracy skills to:

match electrical components and part identification numbers to workplace instructions, vehicle and component part lists, and manufacturer specifications

interpret vehicle electrical measurements and readings

measure voltage, current and resistance and use basic mathematical operations, including addition and subtraction, to calculate deviations from manufacturer specifications.

Planning and organising skills to:

plan own work requirements and prioritise actions to achieve required outcomes and ensure tasks are completed within workplace timeframes.

Technology skills to:

use specialised equipment, such as multimeters and scan tools.


Range Statement

This section specifies work environments and conditions that may affect performance. Essential operating conditions that may be present (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) are included. Bold italicised wording, if used in the performance criteria, is detailed below.

Safety requirements must include:

work health and safety (WHS) and occupational health and safety (OHS) requirements, including procedures for:

identifying hazards and controlling risks associated with:

working with high voltages in BEV electrical systems

wearing jewellery while working around high electrical currents

determining appropriate procedures for minimising risk associated with hazards, including applying electrical safety precautions:

using personal protective equipment (PPE), including electrical safety gloves with 1000 volt rating and HV insulating mat with Australian standards rating

identifying and using fire safety equipment as appropriate

using the ‘one hand rule’

following live system warning tags and signs

depowering the vehicle

isolating the HV RESS electrical supply

stabilising the vehicle electrical system.

Tools and equipment must include:

those specified in the specific vehicle service maintenance procedures, including:

digital multimeter with Cat III 1000 volt rating

insulation tester

oscilloscope

scan tool

residual voltage tester, if specified in original equipment manufacturer (OEM) test requirements.

Environmental requirements must include:

procedures for trapping, storing and disposing of waste released from traction motor speed control systems.


Sectors

Technical - Hybrid Vehicle and Battery Electric Vehicle


Competency Field

Electrical