Dtc U1104 Lost Communication With Driving Support Ecu


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK FOR DTC

CHECK HARNESS AND CONNECTOR (MILLIMETER WAVE RADAR SENSOR - BATTERY AND BODY GROUND)

CHECK HARNESS AND CONNECTOR (DRIVING SUPPORT ECU - BODY GROUND)

CHECK HARNESS AND CONNECTOR (MILLIMETER WAVE RADAR SENSOR - DRIVING SUPPORT ECU)

REPLACE DRIVING SUPPORT ECU

CHECK FOR DTC

CHECK CAN COMMUNICATION SYSTEM

DTC U1104 Lost Communication with Driving Support ECU

DTC U1104 Lost Communication with Driving Support ECU


DESCRIPTION


DTC Code
DTC Detection Condition
Trouble Are
U1104
When the ignition switch is ON, a communication error between the millimeter wave radar sensor assembly and driving support ECU is detected for 1 second.
  1. Harness or connector
  2. Millimeter wave radar sensor assembly
  3. Driving support ECU
U1104
When the ignition switch is ON, communication stops between the seat belt control ECU and driving support ECU for 1 second or more.
  1. Seat belt control ECU
  2. CAN communication system
  3. Driving support ECU

WIRING DIAGRAM


Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Pre-Crash Safety.Pre-Crash Safety System. Dtc U1104 Lost Communication With Driving Support Ecu


INSPECTION PROCEDURE

NOTICE:
  1. When the millimeter wave radar sensor assembly is replaced with a new one, adjustment of the radar sensor beam axis must be performed (LandCruiser RM000000WQG01ZX.html).
  2. Inspect the fuses for circuits related to this system before performing the following inspection procedure.
  3. Confirm that the connector is securely connected, as a partially connected connector may be the cause of this DTC being output.
1.CHECK FOR DTC

  1. Clear the DTCs (LandCruiser RM0000043K500GX.html).

  1. Check for DTCs (LandCruiser RM0000043K500GX.html).

    Result
    Result
    		Proceed to
    DTC U1104 is not output
    		A
    DTC U1104 is output from driving support ECU (Pre-Crash 2)
    		B
    DTC U1104 is output from seat belt control ECU (Pre-Crash)
    		C


B
Go to step 2

C
Go to step 7
A

USE SIMULATION METHOD TO CHECK (LandCruiser RM000003YMJ00XX.html)

2.CHECK HARNESS AND CONNECTOR (MILLIMETER WAVE RADAR SENSOR - BATTERY AND BODY GROUND)


    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Pre-Crash Safety.Pre-Crash Safety System. Dtc U1104 Lost Communication With Driving Support Ecu

  1. Disconnect the A15 sensor connector.

  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage :
    Tester Connection
    		Switch Condition
    		Specified Condition
    A15-5 (IGB) - Body ground
    		Ignition switch ON
    		11 to 14 V
    Ignition switch off
    		Below 1 V

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A15-2 (SGND) - Body ground
    		Always
    		Below 1 Ω
Text in Illustration
*a
Front view of wire harness connector
(to Millimeter Wave Radar Sensor Assembly)


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.CHECK HARNESS AND CONNECTOR (DRIVING SUPPORT ECU - BODY GROUND)


    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Pre-Crash Safety.Pre-Crash Safety System. Dtc U1104 Lost Communication With Driving Support Ecu

  1. Disconnect the G119 ECU connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    G119-25 (GND) - Body ground
    		Always
    		Below 1 Ω
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to Driving Support ECU)


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.CHECK HARNESS AND CONNECTOR (MILLIMETER WAVE RADAR SENSOR - DRIVING SUPPORT ECU)

  1. Disconnect the A15 sensor connector.

  1. Disconnect the G119 ECU connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A15-4 (LRRD) - G119-38 (LRRD)
    		Always
    		Below 1 Ω
    A15-4 (LRRD) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.REPLACE DRIVING SUPPORT ECU

  1. Replace the driving support ECU (LandCruiser RM000002OJO01NX.html).


NEXT


6.CHECK FOR DTC

  1. Clear the DTCs (LandCruiser RM0000043K500GX.html).

  1. Check for DTCs (LandCruiser RM0000043K500GX.html).

    OK:
    DTC U1104 is not output.


NG
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY (LandCruiser RM000002MC401LX.html)
OK

END (DRIVING SUPPORT ECU IS DEFECTIVE)

7.CHECK CAN COMMUNICATION SYSTEM

  1. Select "Bus Check" from the "System Select" screen on the intelligent tester.

  1. Select "Communication Malfunction DTC" from the "Bus Check" screen, and then select "Enter".

    Result
    Result
    		Proceed to
    CAN DTC is not output
    		A
    CAN DTC is output (for LHD with Entry and Start System)
    		B
    CAN DTC is output (for LHD without Entry and Start System)
    		C
    CAN DTC is output (for RHD with Entry and Start System)
    		D
    CAN DTC is output (for RHD without Entry and Start System)
    		E


B
GO TO CAN COMMUNICATION SYSTEM (LandCruiser RM000000WIB0ECX.html)

C
GO TO CAN COMMUNICATION SYSTEM (LandCruiser RM000000WIB0EDX.html)

D
GO TO CAN COMMUNICATION SYSTEM (LandCruiser RM000000WIB0EEX.html)

E
GO TO CAN COMMUNICATION SYSTEM (LandCruiser RM000000WIB0EFX.html)
A

USE SIMULATION METHOD TO CHECK (LandCruiser RM000003YMJ00XX.html)