Diagnose and rectify faults in an electric vehicle powertrain and ancillary systems
Overview
This standard covers the competence and knowledge technicians need to safely diagnose and rectify electrical, mechanical and fluid component faults in an electric vehicle powertrain and high voltage ancillary system, NOT including the high voltage battery, which is covered by a separate NOS (IMIEV10). The standard also ensures that the technician is aware of the effect that high voltage component technology has on other vehicle systems.
For the purposes of this standard, an electric vehicle is any vehicle that is in part or wholly electrically propelled. This would include:
- Hybrid (HEV) - to include mild/micro hybrid vehicles where the voltage is considered dangerous.
- Plug-in Hybrid (PHEV)
- Extended Range Electric Vehicle (ER-EV) or Range Extended Electric Vehicle (RE-EV)
- Battery Electric Vehicle (BEV) or Pure Electric Vehicle (PEV)
- Fuel Cell Electric Vehicle (FCEV).
Warning: It has been recommended by industry experts that only those with suitable training and experience on working with electric vehicles should carry out the functions below. This may involve some diagnostic testing on the live system, appropriate to the level of competency.
Performance criteria
You must be able to:
P1 Use suitable personal and vehicle protective equipment appropriate to the diagnosis and rectification activities carried out
P2 notify all relevant persons of your intention to work on a high voltage system
P3 Support the identification of faults, by reviewing vehicle:
P3.1 technical data
P3.2 diagnostic test procedures
P4 Prepare the vehicle systems and work area for safe working procedures as appropriate to the vehicle and the nature of the fault
P5 Prepare, check and use all the required equipment following manufacturer’s instructions
P6 Use diagnostic methods which are relevant to the symptoms presented
P7 Collect sufficient diagnostic information in a logical and systematic way to enable an accurate diagnosis of the high voltage system faults
P8 Identify and record any system deviation from manufacturer’s specifications accurately
P9 Ensure your assessment of components and units identifies their condition and suitability for repair or replacement
P10 Promptly inform the relevant person(s) where repairs are uneconomic or unsatisfactory to the customer
P11 Carry out all diagnostic and rectification activities following:
P11.1 manufacturer’s instructions
P11.2 recognised repair methods
P11.3 your workplace procedures
P11.4 health, safety and environmental requirements
P12 Work in a way which minimises the risk of:
P12.1 damage to other vehicle systems
P12.2 damage to other components and units
P12.3 injury to self and others
P13 Ensure all repaired and replacement components and units conform to the vehicle operating specification and any legal requirements
P14 Adjust components and units, when necessary, correctly to ensure that they operate to system requirements
P15 Promptly record and report any additional faults you notice during the course of work
P16 Use testing methods which are suitable for assessing the performance of the rectified system
P17 Ensure the rectified system performs to the vehicle operating specification and any legal requirements prior to return to the customer
P18 Follow workplace procedures in case of emergency
P19 Ensure your records are accurate, complete and passed to the relevant person(s) within the agreed timescale and in the format required
P20 Complete all activities within the agreed timescale
P21 Promptly report any anticipated delays in completion to the relevant person(s)
Knowledge and Understanding
You need to know and understand:
Use of technical information
K1 The different types of electric vehicle
K2 How to find, interpret and use sources of information on high and low voltage electrical and electronic, mechanical and fluid system operating specifications, diagnostic test procedures, repair procedures and legal requirements
K3 Vehicle operating specifications relating to high and low voltage electrical, electronic, mechanical and fluid systems for the vehicle(s) on which you work
K4 The importance of using the correct sources of technical information for electric vehicle system diagnosis and rectification
Legislative and organisational requirements and procedures
K5 the legislation, industry codes of practice or guidelines and workplace procedures relevant to:
K5.1 health and safety
K5.2 the environment (including waste disposal)
K5.3 appropriate personal and vehicle protective equipment
K5.4 legal requirements relating to the vehicle (including road safety requirements)
K6 Your workplace procedures for:
K6.1 recording fault location and correction activities
K6.2 reporting the results of tests
K6.3 the referral of problems
K6.4 reporting delays to the completion of work
K7 How to confirm an electric vehicle is safe to work on and the precautions you should take to ensure the high voltage system cannot be re-energised without your knowledge and agreement
K8 The hazards associated with electric vehicle high voltage systems and batteries
K9 How to reduce the risk of high voltage hazards when working on and around electric vehicles
K10 The implications and effects of electricity through the human body
K11 The signs and symptoms of electrocution
K12 The implications of strong magnetic fields and the effects on medical devices
K13 Workplace procedures that must be followed in the event of electric shock and other emergencies
K14 The hazards associated with electric vehicles when exposed to extreme temperatures, impact and other adverse conditions
K15 How to store, dispose of, recycle and return any removed high voltage components in line with legislative and organisational requirements
K16 How to work safely avoiding damage to other vehicle systems, components and units and contact with leakage and hazardous substances
K17 The hazards associated with a and systems, including alternative fuels and hydrogen fuel cells
K18 The importance of working to agreed timescales and keeping others informed of progress
K19 The relationship between time, costs and productivity
K20 The importance of promptly reporting anticipated delays to the relevant person(s)
High and low voltage component faults, their diagnosis and rectification
K21 How high and low voltage electrical, electronic, mechanical and fluid systems are constructed and operate
K22 How high and low voltage electrical, electronic, mechanical and fluid systems are dismantled, reassembled and adjusted to manufacturer’s specifications
K23 The types and causes of high and low voltage electrical, electronic, mechanical and fluid system, component and unit faults and failures
K24 High and low voltage electrical, electronic, mechanical and fluid component unit and replacement procedures, the circumstances which will necessitate replacement and other possible courses of action
K25 The importance of working to recognised diagnostic and rectification procedures and processes and obtaining the correct information for diagnostic and rectification activities to proceed
K26 The importance of recording diagnostic and rectification information
K27 How to select the most appropriate diagnostic testing method for the symptoms presented
K28 How to carry out systematic diagnostic testing of high and low voltage electrical, electronic, mechanical and fluid systems using prescribed processes or formats
K29 How to assess the condition of high and low voltage electrical, electronic, mechanical and fluid components and units
K30 How to interpret test results and vehicle data in order to identify the location and cause of high and low voltage system faults
K31 How to carry out the rectification activities in order to correct faults in the high and low voltage electrical, electronic, mechanical and fluid systems
K32 The relationship between test methodology and the faults repaired – the use of appropriate testing methods
K33 How to make cost effective recommendations for rectification
K34 The components of all fuel sources and systems on electric vehicles, including hydrogen fuel cells
Electrical and electronic principles
K35 Electrical and electronic principles, including ohms law, voltage, power, current (ac/dc), resistance, magnetism, electromagnetism and electromagnetic induction
K36 Electrical symbols, unit and terms
K37 Electrical and electronic principles associated with high voltage systems, including types of sensors and actuators, their application and operation
K38 The operating principles of electric vehicle components
K39 How electrical and electronic high and low voltage systems operate, including electrical component function, electrical inputs, outputs, voltages and oscilloscope patterns, digital and fibre optics principles
K40 How electrical and electronic systems interlink and interact, including multiplexing
K41 The interaction between electrical, electronic, magnetic, chemical and mechanical components within electric vehicle systems
K42 The principles of chassis and insulated return systems as appropriate to electric vehicles
K43 Specific high voltage circuit protection
Use of diagnostic and rectification equipment
K44 How to prepare and check the accuracy of diagnostic testing equipment
K45 How to use diagnostic and rectification equipment for high and low voltage electrical, mechanical, electronic, and fluid systems, specialist repair tools and general workshop equipment
Vehicle system operation
K46 The main differences between an electric vehicle and a non-electric vehicle and its basic operation, including regeneration
K47 How to safely operate an electric vehicle
K48 The specific manufacturer’s guidelines and the precautions necessary when charging, connecting an auxiliary power source to or towing/lifting an electric vehicle
K49 How to mobilise an electric vehicle safely
K50 The charging systems (types and modes) associated with electric vehicles and how to charge electric vehicles safely
K51 The implications of remote vehicle control
Scope/range
Faults occur within:
1.1. High voltage electrical system and components (including high voltage ancillary units and components and batteries)
1.2. Low voltage electrical and electronic systems and components (including motor generator/charging systems)
1.3. Onboard plug-in charging systems
1.4. Mechanical components
1.5. Fluid systemsDiagnostic methods are:
2.1. sensory
2.2. measurement
2.3. functional testingDiagnostic testing is defined as:
3.1. Identify the fault
3.2. Verify the fault
3.3. Collect further information
3.4. Evaluate the evidence
3.5. Carry out further tests in a logical sequence
3.6. Rectify the problem
3.7. Check all systemsEquipment is:
4.1. diagnostic and rectification equipment for high voltage systems
4.2. diagnostic and rectification equipment for low voltage systems
4.3. diagnostic and rectification equipment for mechanical systems
4.4. diagnostic and rectification equipment for fluid systems
4.5. specialist repair tools
4.6. general workshop equipmentHigh voltage personal protective equipment includes but is not limited to:
5.1. insulated high voltage gloves
5.2. face shield
5.3. electrical/fire resistant clothing/apron
5.4. insulated tools
5.5. rubber matDamage to high voltage components includes but is not limited to:
6.1. overheating
6.2. physical impact damage
6.3. chemical leakage
6.4. smoke
6.5. water damage
6.6. different battery chemistries
6.7. reduction in energy holding capacity
6.8. overcharging due to internal electrical damage
Scope Performance
Scope Knowledge
Values
Behaviours
Skills
Glossary
Additional Information
This section contains examples and explanations of some of the terms used but does not form part of the standard.
Hazards associated with high voltage electrical vehicle components - exist not only during work on high voltage systems, as specified above, but also on all other high-power electrical drive systems and high-pressure storage systems. Vehicle and equipment manufacturers’ guidance should be followed at all times.
High voltage – Regulation No 100 of the Economic Commission for Europe of the United Nations (UNECE) — Uniform provisions concerning the approval of vehicles with regard to specific requirements for the electric power train, states that: ‘High Voltage’ means the classification of an electric component or circuit, if its working voltage is > 60 V and ≤ 1 500 V DC or > 30 V and ≤ 1 000 V AC root mean square (rms). Electricity at Work Regulations (1989), and associated HSE guidance should be followed at all times.
N.B. Some electric vehicles may operate at voltages below or above industry recognised standards.
Sensory testing methods - Include looking, listening, smelling, touching for temperature or vibration.
Sources of information applicable to electric vehicles - Examples include hard copy manuals, data on computer and data obtained from on- board diagnostic displays.
Vehicle - any vehicle that is in part or wholly electrically propelled. This would include:
- Hybrid (HEV) - to include mild/micro hybrid vehicles where the voltage is considered dangerous.
- Plug-in Hybrid (PHEV)
- Extended Range Electric Vehicle (ER-EV) or Range Extended Electric Vehicle (RE-EV)
- Battery Electric Vehicle (BEV) or Pure Electric Vehicle (PEV)
- Fuel Cell Electric Vehicle (FCEV)