Relay Box (Interior) Description and Operation

Description

Battery Saver Auto Shut-Off System

Abbreviation	Description
ACU	Airbag Control Unit
ADM	Assist Door Module
B_CAN	Body Controller Network
BCM	Body Control Module
BCW	Blind-Spot Collision Warning Indicator
C_CAN	Chassis Controller Area Network
CLU	Cluster Module
DATC	Dual Automatic Temperature Control
DDM	Driver door module
ESC	Electronic Stability Program
Emergency Call	Engine Control System
LKA	Lane Keeping System
M_CAN	Multimedia Controller Network
MDPS	Motor Driven Power Steering
P_CAN	Power Train Controller Area Network
PSM	Power Seat Module
CAC	Steering Wheel Angle Sensor
SJB	Smart Junction Box
SMK	Smart Key Unit
PAS	Park Assist System
TCU	Transmission Control Unit
SCP	Tire Pressure Monitoring System
VDC	Vehicle Dynamic Control
TMU	Telematics System
ABS	Anti-Lock Braking System (ABS)
CCS	Smart Cruise Control

Smart Junction Box (SJB) General Function: Interior Junction Block + some BCM functions. It controls loads through CAN communication and IPS.

IPS stands for Intelligent Power Switch, which uses semiconductor technology. It replaces the current function of fuses and relays. (The IPS device protects the load current control function from overcurrent.)

SJB Control Input

1. 1
   Switch Signal Input

   1. Assist Seat Belt Switch, Door Switch, Driver Seat Belt Switch, Rear Left Door Switch, Rear Right Door Switch, IGN1 Switch, IGN2 Switch, Brake Fluid Level Sensor, Trunk Lid Handle Switch, HID Headlamp (Option), Hazard Lamp Switch, Low Beam Headlamp Switch, Hood Switch, Left Front/Rear Turn Signal Switch, Right Front/Rear Turn Signal Switch, Parking Brake Switch, Driver Door Lock/Unlock Control Status, Assist Door Lock/Unlock Control, Rear Left Door Lock/Unlock Status, Rear Right Door Lock/Unlock Status, Driver Door Switch, Driver Door Lock Switch, Driver Door Key Unlock Switch, Driver Door Window Lock Switch, Driver Door Window Unlock Switch
   2. IPS & ARISU: Left Headlamp Low Beam, Right Headlamp Low Beam, Left Headlamp High Beam, Right Headlamp High Beam, Room Lamp, Outside Left Tail Lamp, Outside Right Tail Lamp, Left Front/Rear Turn Signal, Right Front/Rear Turn Signal, DRL Left Lamp, DRL Right Lamp, Body Cut Resistance Control, Front Left Turn Signal Output, Front Right Turn Signal Output
   3. Relay Control: Rear Window Defroster Relay, Trunk Lid Relay, Windshield Defroster Relay, Headlamp High Beam Relay, Memory Fuse Relay, Door Lock/Unlock Relay, Power Window Wake-Up Relay 2, Door Lock Turn Relay
2. 2
   SJB Protection

   1. PCL (Programmable Current Limiter) Functions
      • Replaces the current function of the junction box fuse to protect the wire.
      • How it works: If the lamp current exceeds the standard level, the lamp current is cut off to protect the lamp.
      • Lamp shut-off time: 300 ms or less.
      • Applied load: Applies to all controlled lamp loads by SJB.
      • Output the DTC according to the fault detection condition.
   2. OCL (Open Current Limit)
      • Detects an open lamp condition and informs the user of it.
      • How it works: Determine the lamp current and if it is below the standard level, the lamp operation is replaced.
      • Applied load: Applied to turn signal lamp channel 4.
      • Output the DTC according to the fault detection condition.
3. 3
   SJB Fail-Safe Function

   1. When the SJB has a faulty MCU (not operating due to physical damage or external electrical shock), the low beam headlamps and the inner and outer tail lamps are turned on to ensure driver visibility, if IGN2 is on and the headlamp low beam switch is on.
   2. When data transmission/reception fails due to a fault in the CAN communication line connected to the SJB module (high and low line open, high/low BAT short, high/low GND short), the low beam headlamps and inner/outer tail lamps are turned on if IGN2 is on and the headlamp dimmer switch is on.
4. 4
   Battery Saver Auto Shut-Off System

   1. Description: Automatically cuts off power supply to loads to reduce unnecessary dark current according to vehicle condition.

      

      

   2. The SJB has 3 modes: Normal Mode, Sleep Mode, and Power Off Mode. Dark current is automatically cut off in Sleep Mode.
      • Sleep entry condition: IG OFF, constant input switch, CAN network is not active.
      • Sleep cancel condition: Any switch input, CAN network is active, KEY ON, IGN ON.
      • Power Off condition: The timer set time used to cut off load power expires.
      • "Normal Mode": The SJB function is normally active.
      • Sleep Mode: A low power consumption mode activated to reduce power consumption of the SJB or IPM. The automatic dark current cut-off function is activated.
      • Power Off Mode: MCU and peripheral circuit power is cut off to minimize power consumption. Operation stops.
   3. Description - Automatic Dark Current Cut-off

      

      Before Delivery to Customer	Fuse switch OFF.
      All doors closed and door lock RKE or constant switch status (Automatic dark current cut-off scenario starts.) After the Sleep state for 5 min. SJB power off (SJB dark current: 200 μA) and power cut of lamp / Multimedia wake-up / Immobilizer

      
      

      After Delivery to Customer	Fuse switch ON.
      All doors closed and constant switch status: C_BAState=OFF. (Automatic dark current cut-off scenario starts.) After the "sleep" state, the state lasts 20 min. For RKE door lock: C_BAState=ON & Trunk Open=CLOSE (Automatic dark current cut-off scenario starts.) After Sleep state 35–65 s (wait time for other units: 30-60 s + SJB sleep counted as 5 s)

   4. Problem when the fuse switch is incorrectly set: If the fuse switch is set to OFF (before delivery to the customer) by the customer or a technician and the automatic dark current cut-off function is activated, the following problems may occur.

      Symptom	Related Part
      Door lock/unlock and trunk open are not activated by RKE. (Wake-up of each module is not activated.)	BCM
      Digital clock is reset. (Memory is reset.)	Digital Clock
      Audio setting values (volume, frequency tuning) are reset. (Memory is reset.)	Audio

      
      * If the fuse switch is set to OFF (before delivery to the customer), BCM power, digital clock and audio are turned off.