What does code P0D18 mean?

DTC codes / P0Dxx · Hybrid propulsion / P0D18

P0D18Battery Charging System A High Voltage Interlock Circuit High

P0D18 indicates that the battery charging system's high-voltage interlock loop has reported a circuit-high condition, meaning the control module sees an abnormally high voltage or an open circuit on the interlock signal line. The interlock is a safety circuit that confirms high-voltage connectors are properly seated before the system allows charging or discharge, and this code sets when the monitoring circuit detects a voltage above the expected threshold.

SystemPowertrain

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaHybrid propulsion

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.