Home >> Toyota >> 2025 >> Prius Plug-In Hybrid SE >> Repair and Diagnosis >> Hybrid/Electric Powertrain >> Testing and Diagnosis >> Hybrid Battery System (PHEV) - Diagnostic Codes (4 Of 4) & Circuit Tests >> HYBRID BATTERY SYSTEM (for PHEV Model) >> DTC P1B4B-73: Hybrid/EV Battery Heater Relay Actuator Stuck Closed [03/2023 - ] >> Component Operating Range