Kia Cee'd: Fuses and Relays / Relay Box (Passenger Compartment) Description and operation

Kia Cee'd JD Service Manual / Body Electrical System / Fuses and Relays / Relay Box (Passenger Compartment) Description and operation

Description

Smart Junction Box(SJB)

1.	General function : Interior Junction Box + some functions of BCM It controls loads with CAN communication and IPS.

Main function

–	Low speed CAN communication(100 kbps)

–	Self diagnostics(Lamp open/short)

–	Fail safe(When MCU/CAN is fail, Head lamp / Tail lamp directly drive)

–	Protection of bulb over-voltage(PWM function)

–	Cut of Over-load and Short : PCL(Program Current Limit)

Function

1.	Door Switch After judging the position of the contact switch, the SJB sends CAN messages to other modules.

2.	Door Lock/Unlock Relay The SJB receives commands from the BCM, operating the Door Lock/Unlock relay.

3.	Door Unlock State After judging the position of the contact switch, the SJB sends CAN messages to other modules.

4.	Door Key Lock/Unlock Switch After judging the position of the contact switch, the SJB sends CAN messages to other modules.

5.	Power Window Relay The SJB receives commands from the BCM, operating the Power Window relay.

6.	Rear Window Deicer Relay & Front Window Deicer Relay The SJB receives commands from the BCM, operating the Rear Window Deicer Relay & Front Window Deicer relay.

7.	Driver Seat Belt Switch After judging the position of the contact switch, the SJB sends CAN messages to other modules.

8.	Tail Gate Switch After judging the position of the contact switch, the SJB sends CAN messages to other modules(BCM,CLU). SJB send CAN message of Tailgate Status to SMK.

9.	Hood Switch After judging the position of the contact switch, the SJB sends CAN messages to other modules.

10.	Lamp The SJB receives commands from the BCM, operating the each lamp according to those.

11.	Lamp State After judging a state of each lamp, the SJB sends CAN messages to other modules.

12.

Hazard and Turn Signal Lamp

–	An Operating Condition : When the key box is ON or operating. (IGN1 or IGN2)

–	While the Turn Signal Lamps are operated, if more than 1 load is at Open Load or Short to GND state, double blinking would be performed.

–	While the Hazard Lamps are operated, if more than 3 load is at Open Load or Short to GND state, double blinking would be performed.

–	Double Blinking : That means blinking is operated twice faster than normal operating.

–	When the state of Hazard and Turn Signal Lamp are over current or short, all relevant load output of its side is OFF.

13.	Shift Lever ‘R’Signal Switch After judging the position of the contact switch, the SJB sends CAN messages to other modules.

14.	Brake Fluid/Park Break Switch After judging the position of the contact switch, the SJB sends CAN messages to other modules.

15.	Fuse Switch After judging the position of the contact switch, the SJB sends CAN messages to other modules.

16.	Tail Gate Release Relay The SJB receives commands from the BCM, operating the Tail Gate Actuator.

17.	Burglar Horn Relay The SJB receives commands from the BCM, operating the Burglar Horn.

18.	Rear Wiper Relay The SJB receives commands from the BCM, operating the Rear Wiper.

19.	Mirror Folding/Unfolding Relay After judging the position of the contact switch or receiving commands from the BCM, the SJB operates the Mirror Folding, Unfolding Relay and sends the Mirror Command Mode Status to the other modules.

Auto cut system of dark current

1.	Description : It cuts automatically power to be provided with load for reducing useless dark current according to vehicle state.

SJB had 3 modes, "Normal Mode", "Sleep Mode", "Power Off Mode". Auto cut of dark current practice in "Sleep Mode".

–	"Sleep" condition : IG OFF, constant input switch, CAN network doesn't activate.

–	"Sleep" resolutive condition : Any switch inputs, CAN network activates, KEY ON, IGN ON

–	"Power OFF" condition : The setting time of timer which is used by cutting a load power expires.

–	"Normal Mode" : SJB function normally activates.

–	"Sleep Mode" : It is low power mode and activates for reducing electricity consumption of SJB or IPM. Auto cut of dark current function activates.

–	"Power OFF Mode" : Power of MCU and circumferential circuit is cut for minimizing electricity consumption. Operation stops.

The explanation - The auto cut of dark current

Before delivering to customer	Fuse switch OFF
•All door close & RKE door lock or Constant switch state (Auto cut of dark current scenario starts.) -After "sleep" state is for 20 min. -SJB power down(SJB dark current : 200 μA) and cutting power of Interior Lamp/Multimedia/Wake up
After delivering to customer	Fuse switch ON
•All door close & Constant switch state : C_BAState=OFF (Auto cut of dark current scenario starts.) -After "sleep" state is for 20 min. -SJB power down(SJB dark current : 200 μA) and cutting power of Interior Lamp Load •In case RKE door lock : C_BAState=ON & Tail Gate=CLOSE (Auto cut of dark current scenario starts.) -After "Sleep" state 35s~65s (Waiting time of other unit : 30~60s + SJB sleep counts 5s) -SJB Powerdown(SJB dark current : 200 μA) and cutting power of Interior Lamp Load

Problem when fuse switch setting is wrong

: If a fuse switch is set to OFF(Before delivering to customer) by a customer or technician and auto cut function of dark current activates, below problems may happen.

Symptom	Related part
•Door lock/unlock, tailgate open don't activate by RKE. (Wakeup of each module don't activate.)	BCM
•Digital clock is reset.(Memory is reset.)	Digital clock
•Setting value of audio(Volume, Frequency setting) is reset. (Memory is reset.)	Audio

*If fuse switch OFF(before delivering to customer) is set, power of BCM, Digital clock and audio is shut off.

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