Pre-Charge Circuit
A system that gradually energizes high-voltage circuits to prevent current surges.
When an EV is powered on, the pre-charge circuit uses resistors to limit inrush current from the battery to the inverter. This prevents component stress and arcing. Once voltage equalizes, contactors close for full current flow. Malfunctioning circuits can cause startup errors or relay damage. Proper operation ensures smooth and safe HV activation.
Related Diagnostic Guide
This topic is part of CHEPQ’s system-level diagnostic framework.
For a broader understanding of how this component is analyzed in real-world diagnostics, refer to the following guide:
Applying This Knowledge in Practice
The diagnostic principles discussed above are commonly applied in real-world vehicle diagnostics. To put this knowledge into practice, explore professional automotive diagnostic tools designed to support system testing, fault analysis, and troubleshooting across modern vehicles.