Beginner
Quick Diagnosis
Charging & Starting
Cranks slowly and will not start
A petrol hatchback turns over sluggishly and refuses to fire after standing for a week. Decide whether this is a battery, a starting circuit or a fuel problem.
- Volkswagen Golf 2016 · Petrol, manual · 1.4 TSI
- Estimated duration: 15 min
- Pass mark: 60
Scenario overview
Customer complaint
“It has been standing for a week and now it just turns over slowly and won’t start.”
Initial symptoms
Engine cranks noticeably slowly. No attempt to fire. Battery warning lamp dim during cranking. Headlights noticeably dim when cranking.
Initial observations
Vehicle starts fine from a jump pack. Battery has not been replaced in at least four years.
Relevant history
Short journeys only for the last six months. No recent electrical work.
Scenario
The customer reports the car has been standing and now turns over slowly before failing to start. Your job is to establish the cranking quality first and follow the evidence.
Learning objectives
- Establish cranking quality before condemning a component.
- Distinguish a battery fault from a starter or fuel fault.
- Confirm the repair with a repeat measurement.
Diagnostic tools at your disposal
- Battery open-circuit and cranking voltage — Multimeter
- Charging system output — Charging test
- Read fault codes — OBD scanner
- Visual inspection of battery and terminals — Visual inspection
How you are scored
- Relevant diagnostic tests30
- Interpretation of results20
- Final diagnosis25
- Repair selection15
- Final verification10