Fiat 500 1.2 69bhp — Ignition Coil Pack Failure
Coil packs break down internally with heat and age, causing severe misfires under load.
Severity
ModerateDIY Difficulty
Easy
Est. Cost
£50–£150
OBD Codes
P0300P0301P0302P0303P0304Engine
Typical layout and location for the Engine assembly.
Symptoms
- Engine hesitates and jerks when accelerating hard
- Flashing EML light during misfire
- Rough, lumpy idle
- P0301-P0304 fault codes
Root Cause
The insulation inside the pencil coil breaks down due to engine heat. The spark then jumps to the cylinder head instead of crossing the spark plug gap.
How To Fix
- Read OBD codes to identify which cylinder is misfiring (e.g., P0302 = Cyl 2).
- Swap the coil pack to another cylinder and re-read codes to confirm the coil is at fault.
- Replace coil pack (£30-60 each).
- Advised to replace spark plugs at the same time.
Estimated Repair Costs
| Repair Option | Est. Cost (GBP) |
|---|---|
| DIY (parts only) | £20–£60 |
| Independent Garage | £50–£150 |
| Main Dealership | £80–£240 |
Other Faults on This Variant
Exhaust Back Box Corrosion
MinorThe mild steel exhaust back box rots through exceptionally quickly, often causing the exhaust to snap and drag on the floor.
Body Control Module (BCM) / Wiring Loom Failure (Hatch Wiring)
ModerateElectrical gremlins are common on the Fiat 500. The most notorious is the wiring loom snapping where it passes from the body into the boot lid/hatch.
Air Conditioning Condenser Leak (Stone Damage)
MinorThe air conditioning condenser is mounted at the very front of the cooling pack, making it highly susceptible to stone damage from the road, leading to refrigerant loss.
Disclaimer: Repair cost estimates are indicative and based on community data. Always get a quote from a qualified mechanic before proceeding with any repair.