Insulation Monitoring (Isolation Fault)
Insulation monitoring checks that high-voltage parts are electrically isolated from the car body.
What is Insulation Monitoring (Isolation Fault)?
It measures resistance between HV and chassis. Low values trigger warnings. Water ingress is a common cause. Common causes include water in connectors, damaged cables, a faulty heater or a compressor with the wrong oil. The car may still drive with a warning or may refuse to start, depending on severity. Specialist insulation testers are used to locate the faulty component.
How it works
The system applies a test voltage and measures leakage.
Why it matters for your car
An isolation fault can stop charging or driving. Repairs require HV-trained technicians.
Other terms
- ACEA Oil Specification
- Active Aerodynamics
- Axial Flux Motor
- Car Valuation
- Control Unit Reprogramming (Flashing)
- Cooling Fan
- Engine Braking
- Engine Valve
- Idler Pulley
- New Car Warranty
- Panoramic Roof (Glass Roof)
- Relative Compression Test
- Rinseless Wash
- Roll Cage
- Swirl Flaps
- Swirl Marks
- Tonneau Cover
- Tread Depth
- Wallbox (Home Charger)
- Wiper Blade