Vehicle Maintenance, Servicing and Diagnostics
This domain is about keeping a vehicle reliable and finding faults logically. The exam asks for service schedules, daily and periodic checks, fluid and torque specifications, job-card documentation, and the diagnostic sequence from driver complaint to verified repair.
Servicing
- Daily or pre-drive checks: engine oil level, coolant, brake fluid, tyre pressure and condition, lights, wipers, and leaks under the vehicle.
- Periodic items: engine oil and filter, air filter, fuel filter, spark plugs, brake pads, coolant, gearbox oil, wheel alignment and balancing, suspension inspection.
- Free services are labour-free within the warranty period; paid services follow. Every service must be entered in the logbook because warranty claims depend on it.
- Use a torque wrench for critical fasteners such as wheel nuts, cylinder head bolts and suspension joints. Over-torquing stretches bolts and warps heads.
Diagnostic sequence
- Interview the driver and confirm the symptom.
- Visual and basic checks: fluids, belts, fuses, battery terminals.
- Read DTCs and live data; compare with specifications.
- Test the circuit or component: compression test, fuel pressure, spark test.
- Repair, road test, then re-read codes.
Clearing a code without repairing the cause is not a diagnosis.
Worked example
Complaint: misfire with DTC P0301 (cylinder 1). Swap the coil and plug from cylinder 1 to cylinder 2, then re-read. If the code moves to P0302, the coil or plug is faulty. If it stays on cylinder 1, suspect compression, injector or wiring, so run a compression test. This swap-and-re-read method separates ignition faults from mechanical ones in a single test.
Traps that cost marks
Replacing parts on a hunch. Clearing codes and returning the vehicle. Overfilling engine oil. Using water instead of coolant. Dismissing a tyre-pressure warning as a faulty sensor without checking pressures.