Hyundai Ioniq: High Voltage Battery Control System / Description and operation

Hyundai Ioniq (AE) 2017-2025 Service Manual / Hybrid Control System / High Voltage Battery Control System / Description and operation

Description

The high voltage battery system consists of the BMS ECU (Battery Management System ECU), Power Relay Assembly (PRA), safety plug, battery temperature sensor, and battery ambient sensor. Especially the BMS ECU controls SOC (State Of Charge), power, cell balancing, cooling and troubleshooting of the high voltage battery system.

The PRA includes main relays (positive, negative), pre-charge relay, pre-charge resistor and battery current sensor.

[Main Functionalities]

Item

Functionality

SOC Control

•	Optimize SOC by using voltage, current, temperature of the high voltage battery

Power control

•	Predict available battery power, prevent from over-charging or discharging, improve durability and maximize charging/discharging energy by calculating optimum charging & discharging energy in accordance with the vehicle state

Power Relay control

•	Supply or shut off the battery power when IG ON/OFF

•	Prevent from negligent accident by high voltage system trouble

Cooling System control

•	Sustain the optimum temperature by controlling variable cooling fan speed in accordance with the maximum system temperature and deviation among battery modules

Troubleshooting

•	Diagnose system fault

•	Limit battery power in various fail-safe level

•	Control power relays in case of system trouble

•	SOC (State Of Charge) : Available energy of the high voltage battery

High Voltage Battery Control System

Specifications

SpecificationSafety Plug▷ Specification Item Specification Rated Voltage (V) 400 Rated Current (A) 80 Fuse Rated Current (A) 125 Fuse Melting Time Rated Current x 110% Min...

Other information:

Hyundai Ioniq (AE) 2017-2025 Service Manual: Troubleshooting

Troubleshooting Error Item Failure symptom Inspection items Detailed inspections Relevant Parts/ Components Screen displayTFT-LCD screen does not turn on1)Connector attachments2)Components1)Check the connector attachments2)Check B+, IGN and GND wiring3)Check the components Connectors, wiring, fuses, dashboardWarning lightAirbag warning lamp malfunction1)Connector attachments2)C-CAN3)Components1)Check airbag + signal (connectors)2)Check C-CAN (ACU4) signal3)Check the FPC attachment inside the dashboardACU Connectors, wiring, fuses, dashboardMode conversionIntegrated driving mode malfunction1)Connector attachments2)Switch3)Components1)Check the switch input (connector)2)Check the switch signal input(disconnection or shorting)3)Check conversion with dashboard componentSwitch connector, wiring dashboardIlluminationInterior light brightness cannot be controlled...

Hyundai Ioniq (AE) 2017-2025 Service Manual: Power Relay Assembly (PRA). Description and operation

DescriptionThe Power Relay Assembly (PRA) consists of the positive and negative main relays, pre-charge relay, pre-charge resistor and battery current sensor. It is located inside the battery pack assembly and controls the high voltage power circuit between the high voltage battery and inverter by the control signal of BMS ECU...