Knowledge of the Service and Repair of Electrically Propelled Vehicles
This subtopic covers the foundational knowledge required for the safe and effective service and repair of electrically propelled light vehicles. It integrates an understanding of high-voltage hazards, the operational principles of different electric and hybrid vehicle types, and the systematic procedures for vehicle preparation and safe working practices, ensuring technicians can carry out routine maintenance in compliance with industry standards and regulations.
Assessment criteria
Topic Overview
The Skills and Education Group Awards Level 2 Award in Knowledge of the Service and Repair of Electrically Propelled Light Vehicles provides foundational understanding for technicians working on electric and hybrid vehicles. This qualification covers essential safety protocols, high-voltage system principles, and maintenance procedures specific to electrically propelled light vehicles (e.g., cars, vans). It is designed for learners already in or entering the motor vehicle industry, ensuring they can work safely on these increasingly common vehicles.
Key topics include the identification of high-voltage components (such as traction batteries, inverters, and electric motors), understanding of regenerative braking systems, and knowledge of charging infrastructure. The course emphasises the critical importance of isolating high-voltage systems before service or repair, following manufacturer guidelines, and using appropriate personal protective equipment (PPE). This knowledge is vital as the automotive industry transitions towards electrification, making this award highly relevant for career progression.
This qualification fits within the broader Motor Vehicle & Transport sector by bridging traditional mechanical skills with modern electrical expertise. It prepares students for roles such as electric vehicle technician, service advisor, or parts specialist, and provides a stepping stone to higher-level qualifications like the Level 3 Award in Electric/Hybrid Vehicle System Repair and Replacement.
Key Concepts
Core ideas you must understand for this topic
- →High-voltage safety: Understanding the dangers of voltages above 60V DC, the use of insulated tools, and the mandatory isolation procedure (locking off and proving dead) before any work.
- →Traction battery types: Knowledge of lithium-ion (Li-ion) and nickel-metal hydride (NiMH) batteries, their voltage ranges (typically 200-800V), and cooling systems.
- →Regenerative braking: How the electric motor acts as a generator to recover kinetic energy, converting it to electrical energy stored in the battery, and its effect on brake wear.
- →Inverter and converter functions: The inverter changes DC from the battery to AC for the motor; the DC-DC converter steps down high voltage to 12V for auxiliary systems.
- →Charging systems: Differences between AC (Mode 2/3) and DC (Mode 4) charging, connector types (Type 2, CCS, CHAdeMO), and charging times.
Learning Objectives
What you need to know and understand
- 1. Understand the risks and hazards associated with electric and electric/hybrid light vehicles2. Know and understand the different types of electric and electric/hybrid light vehicle, associated technology, components and operating principles3. Know how to prepare an electric and electric/hybrid light vehicle when carrying out routine service and repair procedures4. Know how to work safely on electric and electric/hybrid light vehicles
- 1. Understand the risks and hazards associated with electric and electric/hybrid light vehicles2. Know and understand the different types of electric and electric/hybrid light vehicle, associated technology, components and operating principles3. Know how to prepare an electric and electric/hybrid light vehicle when carrying out routine service and repair procedures4. Know how to work safely on electric and electric/hybrid light vehicles
Assessment Criteria
Key criteria assessors look for in your portfolio
- Award credit for demonstrating the ability to identify and explain the specific electrical hazards (e.g., high voltage, stored capacitive energy) and outline appropriate control measures, including risk assessment and safe systems of work.
- Award credit for accurately describing the key components, operating modes, and energy flow for at least two distinct electric/hybrid vehicle architectures (e.g., battery electric vehicle, series hybrid, parallel hybrid).
- Award credit for correctly outlining the step-by-step procedure to prepare a vehicle for routine service, including isolating the high-voltage system, verifying zero potential, and securing the vehicle against unauthorised re-energisation.
- Award credit for evidencing safe working practices, such as the consistent use of appropriate personal protective equipment (PPE) and insulated tools meeting BS EN 60900, and for explaining the rationale behind these precautions.
- Award credit for accurately identifying high-voltage components (e.g., battery pack, inverter, motor/generator) and explaining their function in at least two different electric/hybrid vehicle types.
- Expect clear demonstration of the correct isolation procedure for high-voltage systems, including isolating the 12V battery, removing the service plug, and verifying zero potential with a calibrated CAT III/IV multimeter.
- Credit responses that detail specific risks such as electrocution, arc flash, thermal runaway, and the use of appropriate personal protective equipment (PPE) like insulated gloves (class 0, 1000V) and face shields.
- Look for evidence of understanding how to prepare a vehicle for routine tasks by referencing manufacturer-specific shut-down procedures, using warning signs, and establishing a safe working perimeter.
Assessment Guidance
Guidance for achieving higher grades
- 💡When responding to written questions, always structure your answers around the key safety hierarchy: identify hazards, isolate/depower, verify dead, and then proceed, ensuring you reference industry standards such as the IMI Electric Vehicle Technician accreditation criteria.
- 💡During practical assessments, use a think-aloud approach to narrate your hazard identification, isolation process, and safety checks; this provides clear evidence of your underpinning knowledge and methodical work ethic.
- 💡For multiple-choice questions, eliminate distractors by recalling that high-voltage is defined as 60V DC or 30V AC RMS, and always prioritise safety steps.
- 💡In written responses, structure answers around the plan-do-review cycle: identify hazards, isolate and confirm safe condition, perform task, and restore vehicle to operational state.
- 💡Reference industry standards such as BS EN 50110-1 and the IET Code of Practice for Electric Vehicle Charging Equipment Installation, even at Level 2, to demonstrate professional awareness.
- 💡When describing components, link function to operating principles (e.g., regenerative braking converts kinetic energy to electrical energy via the motor acting as a generator) to show deeper understanding.
- 💡Always quote specific safety steps from the IET Code of Practice or manufacturer procedures when answering questions on isolation. Generic answers lose marks.
- 💡Use correct terminology: 'electrically propelled light vehicle' not 'electric car', and 'traction battery' not 'car battery'. This shows precise knowledge.
- 💡For questions on regenerative braking, explain the energy flow (kinetic → electrical → chemical) and mention that it reduces brake pad wear but does not replace the hydraulic braking system.
Common Mistakes
Common errors to avoid in your coursework
- Assuming that the high-voltage system is automatically safe once the vehicle is switched off, neglecting the presence of stored energy in capacitors and battery packs that can remain for an extended period.
- Confusing the roles of the internal combustion engine and electric motor in different hybrid configurations, leading to incorrect diagnosis of driveability issues.
- Omitting to consult vehicle-specific technical data or service bulletins before starting work, resulting in incorrect isolation procedures and potential exposure to live high-voltage components.
- Assuming that disconnecting the 12V battery automatically makes the high-voltage system safe, without waiting for capacitor discharge or verifying voltage absence.
- Confusing mild hybrids, full hybrids, plug-in hybrids, and battery electric vehicles, leading to incorrect selection of service procedures.
- Neglecting to use a high-voltage insulation tester when checking tool integrity, or not maintaining tools to VDE standards.
- Misidentifying orange cabling as low-voltage due to lack of colour-coded awareness, or overlooking the presence of multiple high-voltage interlock loops.
- Misconception: Electric vehicles (EVs) are maintenance-free. Correction: While EVs have fewer moving parts, they still require regular checks on coolant, brake fluid, tyres, and high-voltage cable integrity.
- Misconception: It's safe to work on an EV if the key is off. Correction: High-voltage capacitors can retain a lethal charge for minutes after shutdown; always follow the manufacturer's isolation procedure and wait the specified discharge time.
- Misconception: All electric vehicles use the same charging connector. Correction: There are multiple standards (e.g., Type 2 for AC, CCS for DC in Europe, CHAdeMO for some Japanese models); technicians must identify the correct connector for each vehicle.
Frequently Asked Questions
Common questions students ask about this topic
Pass / Merit / Distinction Evidence Checklist
How your portfolio evidence is graded for SKILLS AND EDUCATION GROUP AWARDS Knowledge of the Service and Repair of Electrically Propelled Vehicles
Every vocational unit is marked against named criteria rather than an exam percentage. Your tutor's brief lists the exact codes for this unit — here is what each band is asking you to do.
Demonstrate baseline knowledge, accurate terminology, and core practical application.
Provide detailed analysis, structured explanations, and clear workplace reasoning.
Deliver thorough evaluation, original problem solving, and fully justified recommendations.
Before You Start
Prior knowledge that will help with this topic
- •Basic understanding of electrical principles (voltage, current, resistance, Ohm's Law) is essential before studying high-voltage systems.
- •Familiarity with standard vehicle service procedures (e.g., lifting, wheel removal, fluid checks) helps contextualise the additional steps for EVs.
- •Knowledge of health and safety legislation (e.g., COSHH, PUWER) is beneficial for understanding the legal framework around high-voltage work.
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Key Terminology
Essential terms to know
- 1. Understand the risks and hazards associated with electric and electric/hybrid light vehicles2. Know and understand the different types of electric and electric/hybrid light vehicle, associated technology, components and operating principles3. Know how to prepare an electric and electric/hybrid light vehicle when carrying out routine service and repair procedures4. Know how to work safely on electric and electric/hybrid light vehicles
- 1. Understand the risks and hazards associated with electric and electric/hybrid light vehicles2. Know and understand the different types of electric and electric/hybrid light vehicle, associated technology, components and operating principles3. Know how to prepare an electric and electric/hybrid light vehicle when carrying out routine service and repair procedures4. Know how to work safely on electric and electric/hybrid light vehicles
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