Kia Optima DL3 Quiz
Body Electrical System

Integrated Central Control Unit (ICU)

In this manual: Body Electrical System
General Information — 8Advanced Driver Assistance System (ADAS) — 21Maintenance — 27Engine Mechanical System — 45Engine Electrical System — 11Emission Control System — 11Engine Control System/Fuel System — 25Automatic Transmission — 20Drive Shaft and Axle — 7Suspension System — 22Steering — 7Restraints — 11Brake System — 22Body (Interior and Exterior) — 116Body Electrical System — 90Heating, Ventilation, and Air Conditioning — 32
22steps
~132min
4/5difficulty
Done 0 of 22

Components and Component Location

Component Location

1. Integrated Central Control Unit (ICU)

Description and Operation

Description

The Integrated Control Unit (ICU) combines the Smart Junction Box (SJB) and the Integrated Gateway and Power Management module (IGPM).

System Block Diagram

Function

Item Function
Function Switch Input Receives switch inputs, then sends the switch status to each module via CAN message.
Lamp Control Controls the lamp via IPS upon receiving a command from the IBU via CAN message.
Internal Relay Control Controls the internal relay upon receiving a command from the IBU via CAN message.
External Control Relay Controls the external relay upon receiving a command from the IBU via CAN message.
Dark Current Shutoff System The system automatically cuts power supplied to components to reduce unnecessary dark current depending on vehicle operating conditions, such as shipping and long-term parking.
Diagnostic Trouble Code Troubleshooting Diagnoses the status of loads controlled by the IPS.
Gateway Transmits signals between modules connected to different networks in the vehicle.

* The ICU does not evaluate logic; it is controlled only by CAN commands from other modules.

▶ Independent logic functions: Hazard warning lamps, stop lamps, luggage compartment lamp, steering wheel heater, door lock/unlock

Switch Input

  1. Operation Function

    ▶ Hazard warning switch, seat belt switch, rear door switch, door switch, etc.

  2. Operation Description

    1. Specific operating status of the switch

    2. Switch status messages are sent to other modules (IBU, CGW, DAU, PSM, etc.) via the CAN bus.

IPS Lamp Control

  1. Operation Function

    ▶ Headlamp low/high beam, turn signal lamp, DRL lamp, interior/exterior tail lamp, stop lamp, etc.

  2. Operation Description

    1. Turns the lamp on/off by IBU CAN message.

    2. Detects the current flowing through the lamp via IPS.

    3. The lamp is turned off when an overcurrent is detected (PCL control: current cut-off of the lamp if the reference current is exceeded).

Internal Relay Control

  1. Operation Function

    ▶ Security alarm horn, trunk lid, power windows, etc.

  2. Operation Description

    1. Turns the relay on/off via IBU CAN message.

External Control Relay

  1. Operation Function

    ▶ High beam headlamp solenoid, rear fog lamps, rear window heater, etc.

  2. Operation Description

    1. Turns the relay on/off via IBU CAN message.

Dark Current Shutoff System Deactivated

  1. Operation Description

    1. If CAN and switch inputs are absent for a long time, the output power is shut off sequentially to prevent battery discharge.

    2. If a CAN input or switch input is received while the dark current shutoff system is off, the system is deactivated for normal operation.

Repair Procedures

Inspection

Fuse Inspection

  1. Make sure the fuse holders are secured firmly and the fuses are securely held in place by the holders.

  2. Make sure that each fuse circuit has the correct fuse rating.

  3. Inspect the fuses for damage.

Diagnosis Using KDS

  1. In the body electrical system, faults can be quickly diagnosed using the Korean Diagnostic System (KDS).

    The Diagnostic System (KDS) provides the following information.

    1. Self-diagnosis: check for malfunction and diagnostic trouble code (DTC).

    2. Current Data: Check the system input/output status.

    3. Operation check: Check the operating status of the system.

    4. Special Function: Control of other functions, including parameter setting and zero point adjustment.

  2. Select "Vehicle Model" and "Integrated Central Control Unit (ICU)" to inspect the vehicle using the tester.

  3. Select the "Current Data" menu to view the current input/output data status.

  4. To forcibly activate the input value of the module under test, select the "Activation Test" option.

  5. To change a user setting, select "User Setting".

Removal

  1. Disconnect the negative battery cable.

  2. Remove the mood lamp unit.

    (Refer to Lighting System - "Mood Lamp")

  3. Disconnect the ICU connectors (A).

  4. Remove the retaining clips (A).

  5. Remove the ICU (A) after loosening the mounting nuts.

  6. Disconnect the connectors (A) from the ICU, then disconnect the wiring harness mounting clips.

Installation

  1. Install in the reverse order of removal.

Test yourself

A quick Kia Optima DL3 quiz: every answer comes with an explanation and a link to the manual page.