P0ADC – Hybrid Battery Positive Contactor Control Circuit High

P0ADC Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light)

P0ADC Possible Causes

Faulty System Main Relay,System Main Relay harness is open or shorted,System Main Relay circuit poor electrical connection,Faulty HV control ECU

P0ADC Description

The SMRs (System Main Relays) connect and disconnect the high-voltage power supply circuit in accordance with requests from the HV control ECU. To ensure a reliable operation, they consists of a total of 3 relays (1 for the negative side and 2 for the positive side). To connect, SMR1 and SMR3 turn ON initially. Then, SMR2 turns ON and SMR1 turns OFF. This process protects the circuit from the high-voltage surge current by allowing the limit current to flow via the resistor. To disconnect, SMR2 and SMR3 turn OFF in that order. The HV control ECU checks that the relays have turned OFF properly. The HV control ECU monitors the proper operation of the SMRs (CON1, CON2 and CON3) to check for a malfunction.