Locate and correct motor vehicle electrical faults

This standard is about conducting a range of routine electrical tests and identifying simple faults on a variety of basic electrical components and undertaking suitable correction activities.

P1 select and use appropriate personal and vehicle protective equipment at all times
P2 support the identification of electrical faults, by reviewing manufacturer:
P2.1 technical data
P2.2 diagnostic test procedures
P3 confirm that all tools and equipment are safe prior to use by performing safety and operational checks
P4 check the functionality of the electrical system(s) / component
P5 carry out tests on electrical system(s) relevant to the identified fault on the vehicle
P6 use electrical testing techniques which are suitable for the electrical system(s) / components concerned
P7 carry out all diagnostic & rectification activities following:
P7.1 manufacturers’ procedures
P7.2 industry recognised methods
P7.3 health, safety and environmental requirements
P8 work in a way which minimises the risk of :
P8.1 damage to other vehicle systems, units and components
P8.2 contact with leakage, hazardous substances and high voltage systems
P8.3 damage to your working environment
P8.4 injury to yourself and others
P9 ensure your electrical testing techniques clearly identify the cause/s of identified fault/s
P10 report the results of your tests and any recommendations for further action to the relevant person(s) clearly and accurately in an appropriate format, when necessary
P11 promptly seek the assistance of the relevant person(s) where the results of your testing are unclear
P12 ensure all removed, replaced and repaired components are secure and function as specified by the manufacturer prior to release to the customer
P13 dispose of any removed electrical components safely to comply with legal and environmental requirements in line with your workplace procedures
P14 complete all electrical fault location and correction activities within the agreed timescale
P15 promptly report any anticipated delays in completion to the relevant person(s)

Legislative and organisational requirements and procedures
K1 the current health and safety legislation and workplace procedures relevant to workshop practices and personal and vehicle protection when carrying out electrical fault location and correction activities
K2 statutory legal requirements relating to the vehicle and the components fitted
K3 your workplace procedures for:
K3.1 recording fault location and correction activities
K3.2 reporting the results of tests
K3.3 the referral of problems
K3.4 reporting delays to the completion of work
K4 the importance of working to recognised diagnostic procedures and processes and obtaining the correct information for diagnostic activities to proceed
K5 the importance of working to agreed timescales and keeping others informed of progress
K6 the relationship between time and costs
K7 the importance of promptly reporting any anticipated delays to the relevant person(s)
Electrical and electronic principles
K8 vehicle earthing principles and methods
K9 basic electrical and electronic principles, including Ohms Law, voltage, power, current (AC/DC), resistance, magnetism, electromagnetism and electromagnetic induction
K10 circuit protection
K11 how electrical/electronic systems within motor vehicles operate
K12 electrical/electronic symbols, units and terms
K13 how to interpret wiring diagrams
K14 the hazards associated with working on or near high voltage components
Use of electrical testing equipment and electrical testing techniques
K15 when and where to use voltage, ohm, amp and specific gravity measurements and simple circuit testing techniques
K16 when and where to use voltage, ohm, amp and specific gravity measurements and simple circuit testing techniques
K17 testing techniques to determine the cause(s) of a fault
K18 how to use the electrical testing equipment required
K19 how to conduct tests following electrical safety and workplace procedures
K20 how to determine the suitability of a component based upon calculations using ohms law
K21 how to interpret the results of your tests
K22 how to make recommendations based upon the results of your tests
K23 the importance of basing your recommendations upon the results of your tests
Vehicle electrical equipment faults and their correction
K24 how to identify faults and damage in vehicle electrical systems through effective interpretation of test results
K25 the common underlying causes of faults and damage within the electrical components
K26 the purpose and function of motors, capacitors, resistors, semi-conductors, transistors, actuators and sensors (including active or self-generating and passive or modulating)
K27 how to dispose of any removed electrical components in line with legislation and organisational procedures
K28 how to perform safety and operational checks on the tools and equipment required to remove and replace electrical components
K29 how to check that any replaced electrical components are functioning correctly and the importance of doing so before release to the customer

1. Examples of electrical components include:
   1.1. power storage devices
   1.2. power generating devices
   1.3. vehicle starting devices
   1.4. vehicle lighting devices
   1.5. wiring harness and connection devices
   1.6. vehicle sensors and actuators
   1.7. circuit protection devices
   1.8. infotainment systems
   1.9. telematic / tracking systems
   1.10. security systems
   1.11. communication systems
   1.12. comfort systems
   1.13. safety systems
2. Electrical testing equipment includes:
   2.1. volt meters
   2.2. ammeters
   2.3. ohmmeters
   2.4. battery testing equipment
   2.5. diagnostic equipment
   2.6. oscilloscope
3. Tools and equipment include:
   3.1. hand tools
   3.2. special purpose tools
   3.3. general workshop equipment
   3.4. specialist electrical testing equipment
4. Electrical testing techniques include:
   4.1. voltage measuring
   4.2. current measuring
   4.3. resistance measuring
   4.4. sensory
   4.5. functional

This section contains examples and explanations of some of the terms used but does not form part of the standard.
Agreed timescales
Examples include: manufacturer’s recommended work times, job times set by your company or a job time agreed with a specific customer
Rectification activities
An appropriate repair or replacement that rectifies the fault(s) identified from the diagnostic activities carried out. Post repair diagnostic confirmation of rectification.
Vehicles
These can be any of the following – light vehicles, heavy goods and passenger service vehicles, motorcycles, mopeds and scooters