IsItAGoodCar
Reliability Guide

Common Problems with the
2017 BMW i3 (I01)

The 2017 model year brought a 94Ah/33kWh battery, lifting UK range by around 50 percent and making the i3 viable for longer commutes.

What changed for 2017

  • •94Ah/33kWh battery replaces the 60Ah pack, raising real-world range to about 120-150 miles.
  • •Updated battery-cooling software and motor mapping.
  • •Battery retrofit offered to existing owners in the UK.

Common MOT watch-outs

  • !Rear brake corrosion remains common because regeneration does most of the slowing.
  • !Tyre wear on the driven rear axle; check inner and outer shoulders.
  • !Headlamp aim and cracked lamp lenses on pre-2018 cars.
3
Known Issues
1
Serious
1
Moderate
1
Minor

All Known Issues

KLE (Onboard Charger) Failure

SeriousElectrics & Electronics

The Convenience Charging Electronics (KLE) module can fail, leading to reduced AC charging speeds or a total inability to charge from a wallbox.

Est. Repair Cost: £1,000–£2,500
Warning Signs:

AC charging restricted to 3.7kW (half speed), Car refusing to start an AC charge, Fault message on iDrive

What to Inspect:
  • Test the car on a 7kW or 11kW AC charger and check the draw
  • Check if the updated KLE unit was fitted under warranty
Verified by IsItAGoodCar Research Team

REx Engine Corrosion & Misfires

ModerateEngine

The Range Extender (a 650cc scooter engine) can suffer from internal corrosion or stale fuel if not used regularly. It is sensitive to spark plug and oil condition.

Est. Repair Cost: £500–£1,500
Warning Signs:

REx engine refusing to start, Rough running or "Drivetrain" error when the REx is active, Strong smell of petrol or oil

What to Inspect:
  • Request a manual start of the REx (Maintenance Mode) during the test drive
  • Check the oil and spark plug service history
  • Look for fuel pressure sensor recall completion
Verified by IsItAGoodCar Research Team

12V Auxiliary Battery Failure

MinorElectrics & Electronics

The small 12v battery powers the car's computers. When it fails, the car throws dozens of unrelated error codes and may refuse to engage the high-voltage system.

Est. Repair Cost: £150–£250
Warning Signs:

Random "High Voltage System" errors, Car won't "Ready" or unlock, Screen glitches

What to Inspect:
  • Check the date code on the 12v battery (should be replaced every 4-5 years)
  • If original, budget for immediate replacement
Verified by IsItAGoodCar Research Team

Buying Tips for 2017 BMW i3 (I01)

  • Ask for a BMW battery state-of-health report rather than trusting the range display.
  • Check the charging port for damaged pins and water ingress.
  • Verify the heater and heat-pump function, an expensive failure on early cars.
2014–20162018
Check a 2017 BMW i3 (I01) by Registration