Ford Focus Mk3 1.6 TDCi 115bhp — Alternator / Smart Charge System Failure
Modern vehicles use smart charging systems to reduce engine load, but the complex regulators on the alternators frequently fail.
Severity
SevereDIY Difficulty
Moderate
Est. Cost
£250–£450
OBD Codes
P0620P0622Electrics
Typical layout and location for the Electrics assembly.
Symptoms
- Red battery warning light on dashboard
- 'Charging System Fault' message
- Systems shutting down (radio, power steering) as battery depletes
- Car fails to start
Root Cause
The internal voltage regulator or diode pack on the alternator burns out due to heat and age. Occasionally, a slipping auxiliary belt causes the issue.
How To Fix
- Test battery voltage with engine running (should be 13.8V - 14.7V).
- If below 12.5V, replace the alternator.
- Always replace the auxiliary drive belt at the same time.
- Cost: £250-450
Estimated Repair Costs
| Repair Option | Est. Cost (GBP) |
|---|---|
| DIY (parts only) | £100–£180 |
| Independent Garage | £250–£450 |
| Main Dealership | £400–£720 |
Other Faults on This Variant
DPF Blockage and Forced Regeneration Failure
ModerateDPF blockage is the most reported issue on the Focus Mk3 1.6 TDCi. City driving prevents regeneration, and the DPF warning light becomes a familiar sight for urban Focus diesel owners.
EGR Valve and Cooler Failure
SevereThe EGR valve and cooler on the Mk3 Focus 1.6 TDCi are known to fail together. EGR cooler failure can cause coolant to enter the intake — a more serious failure than a simple blocked valve.
Turbocharger Failure
SevereThe turbocharger on the Focus Mk3 1.6 TDCi is vulnerable to bearing wear from oil sludge and extended service intervals. Failure typically presents as a sudden loss of power with a loud noise.
Disclaimer: Repair cost estimates are indicative and based on community data. Always get a quote from a qualified mechanic before proceeding with any repair.