Lexus IS250 · Service Manual COMMUNICATION SYSTEM

DIAGNOSIS SYSTEM

Troubleshooting


BUS CHECK (COMMUNICATION MALFUNCTION DTC)

HINT:
Only CAN communication system DTCs for each ECU can be displayed on the intelligent tester.

  1. G029877E01
    Select "Bus Check" from the "System select" screen on the intelligent tester.

  2. G029878
    Select "Communication Malfunction DTC" from the "Bus Check" screen, and then select "Enter".

  3. G029879
    Select the system of the DTC to be checked and select "Details".

  4. G029880
    CAN communication system DTC(s) is/are displayed.


BUS CHECK (COMMUNICATION BUS CHECK)

HINT:
The ECUs and sensors that are properly connected to the CAN communication system can be displayed using the intelligent tester.

  1. G029878
    Select "Communication Bus Check" from the "Bus Check" screen.

  2. G029881
    The screen displays the ECUs and sensors that are properly connected to the CAN communication system.

    HINT:
    If ECUs or sensors that should be properly connected are not displayed, there is a communication stop in the system. (Click here)

  3. G029882
    "There is no system connected to the communication bus" is displayed if there are no ECUs or sensors connected to the CAN bus.


CHECK FOR INSTALLED SYSTEMS (ECUS AND SENSORS) THAT ADOPT CAN COMMUNICATION

  1. Systems (ECUs, sensors) that adopt CAN communication vary depending on the vehicle's optional equipment. Check which systems (ECUs, sensors) are installed on the vehicle.

    ECU/Sensor name
    		 Check method
    Skid control ECU
    		 Installed on all vehicles
    Steering angle sensor
    		 Installed on all vehicles
    Yaw rate sensor
    		 Installed on all vehicles
    ECM
    		 Installed on all vehicles
    Distance control ECU
    		 Dynamic radar cruise control
    Gateway ECU
    		 Installed on all vehicles
    Seat belt control ECU
    		 Dynamic radar cruise control
    Power steering ECU
    		 Installed on all vehicles
    Television camera ECU
    		 Parking assist monitor system
    Center airbag sensor
    		 Installed on all vehicles


DTC TABLE BY ECU

HINT:
If CAN communication system DTCs are output, trouble cannot be determined only by the DTCs. Perform troubleshooting according to "HOW TO PROCEED WITH TROUBLESHOOTING" (Click here). (If however, U0235 or U01102 is output alone, see the dynamic radar cruise control system.)

  1. ECM/Intelligent tester display "Engine"

    HINT:
    1. DTC communication uses the CAN communication system.
    2. Distance control ECU data is also output.

    DTC No.
    		 Detection Item
    U0100 (*3)
    		 Lost Communication With ECM/PCM "A"
    U0101 (*1)
    		 Lost Communication With Transfer Case Control Module
    U0122 (*3)
    		 Lost Communication With Vehicle Dynamics Control Module
    U0123 (*3)
    		 Lost Communication With Yaw Rate Sensor Module
    U0126 (*3)
    		 Lost Communication With Steering Angle Sensor Module
    U0235 (*2)
    		 Lost Communication With Cruise Control Front Distance Range Sensor
    U1101 (*3)
    		 Lost Communication With Distance Control ECU
    U1102 (*2)
    		 Lost Communication With radar Sensor
    1. *1: The ECM is malfunctioning if U0101 is output. Replace the ECM.
    2. *2: If U0235 or U1102 is output alone, the CAN communication is normal (See page for Click here U0235, Click here for U1102).
    3. *3: Dynamic radar cruise DTC.

  2. ECM/Intelligent tester display "ECT"

    HINT:
    1. DTC communication uses the CAN communication system.
      DTC No.
      		 Detection Item
      U0100 (*1)
      		 Lost Communication With ECM/PCM "A"
    2. *1: The ECM is malfunctioning if U0100 is output. Replace ECM.

  3. SKID CONTROL ECU/Intelligent tester display "ABS/VSC/TRC"

    HINT:
    DTC communication uses the SIL line.

    DTC No.
    		 Detection Item
    U0073
    		 Control Module communication Bus Off
    U0100
    		 Lost Communication With ECM/PCM "A"
    U0123
    		 Lost Communication With Yaw Rate sensor Module
    U0124
    		 Lost Communication With Lateral Acceleration Sensor Module
    U0126
    		 Lost Communication With Steering Angle Sensor Module

  4. POWER STEERING ECU/Intelligent tester display "EPS"

    HINT:
    DTC communication uses the CAN communication system.

    DTC No.
    		 Detection Item
    U0105
    		 Lost Communication With ECM
    U0121
    		 Lost Communication With Anti-lock Brake System (ABS) Control Module

  5. SEAT BELT CONTROL ECU/Intelligent tester display "Pre-crash Seat Belt"

    HINT:
    DTC communication uses the SIL line.

    DTC No.
    		 Detection Item
    U0100
    		 Lost Communication With ECM/PCM "A"
    U0122
    		 Lost Communication With Vehicle Dynamics Control Module
    U0235 (*4)
    		 Lost Communication With Gateway ECU
    U1101
    		 Lost Communication With Distance Control ECU
    U1102 (*4)
    		 Lost Communication With Radar Sensor
    U0151
    		 Lost Communication With Airbag ECU

    HINT:
    *4: If U0235 or U1102 is output alone, the CAN communication is normal (Click here for U0235, Click here for U1102).

  6. TELEVISION CAMERA ECU/Intelligent tester display "Parking Assist Monitor"

    HINT:
    The DTC is displayed on the multi-display assembly (not displayed on the intelligent tester).

    DTC No.
    		 Detection Item
    5C-42
    		 Steering angle sensor communication line malfunction

  7. GATEWAY ECU

    HINT:
    The gateway ECU is connected to the CAN communication system, but CAN communication DTCs are not output.

  8. CENTER AIRBAG SENSOR

    HINT:
    The center airbag sensor is connected to the CAN communication system, but CAN communication DTCs are not output.


DTC COMBINATION TABLE
DTC
 Trouble Mode
Output from
 Output DTC
 Skid Control ECU Communication Stop Mode
 Steering Angle Sensor Communication Stop Mode
 Yaw Rate Sensor Communication Stop Mode
 Gateway ECU Communication Stop Mode
 ECM Communication Stop Mode
Skid Control ECU
 U0073
 ○
 X
 X
 X
 X
U0100
 □
During driving
 X
 X
 X
 □
During driving
U0123
 ○
 X
 ○
 X
 X
U0124
 ○
 X
 ○
 X
 X
U0126
 ○
 ○
 X
 X
 X
ECM
 U0100
 X
 X
 X
 X
 X
U0122
 □
Control distance
 X
 X
 X
 X
U0123
 X
 X
 □
Control distance
 X
 X
U0126
 X
 □
Control distance
 X
 X
 X
U1101
 X
 X
 X
 X
 X
Power Steering ECU
 U0105
 X
 X
 X
 X
 ○
U0121
 ○
 X
 X
 X
 X
Television Camera ECU
 5C-42
 X
 ○
 X
 X
 X
Seat Belt Control ECU
 U0100
 X
 X
 X
 X
 ○
U0122
 ○
 X
 X
 X
 X
U1101
 X
 X
 X
 X
 X
U0151
 X
 X
 X
 X
 X
DTC
 Trouble Mode
Output from
 Output DTC
 Distance Control ECU Communication Stop Mode
 Seat Belt Control ECU Communication Stop Mode
 Power Steering ECU Communication Stop Mode
 Television Camera ECU Communication Stop Mode
 Center Airbag Sensor Communication Stop Mode
Skid Control ECU
 U0073
 X
 X
 X
 X
 X
U0100
 X
 X
 X
 X
 X
U0123
 X
 X
 X
 X
 X
U0124
 X
 X
 X
 X
 X
U0126
 X
 X
 X
 X
 X
ECM
 U0100
 X
 X
 X
 X
 X
U0122
 X
 X
 X
 X
 X
U0123
 X
 X
 X
 X
 X
U0126
 X
 X
 X
 X
 X
U1101
 X
 X
 X
 X
 X
Power Steering ECU
 U0105
 X
 X
 ○
 X
 X
U0121
 X
 X
 ○
 X
 X
Television Camera ECU
 5C-42
 X
 X
 X
 ○
 X
Seat Belt Control ECU
 U0100
 X
 X
 X
 X
 X
U0122
 X
 X
 X
 X
 X
U1101
 ○
 X
 X
 X
 X
U0151
 X
 X
 X
 X
 ○

HINT:
  1. ○: Set
  2. X: Not set or may be set according to the malfunction part when one side of the CAN branch lines opens.
  3. □: Set under the condition shown in the table
  1. Skid Control ECU Communication Stop Mode: Click here
  1. Steering Angle Sensor Communication Stop Mode: Click here
  1. Yaw Rate Sensor Communication Stop Mode: Click here
  1. Gateway ECU Communication Stop Mode: Click here
  1. ECM Communication Stop Mode: Click here
  1. Distance Control ECU Communication Stop Mode: Click here
  1. Seat Belt Control ECU Communication Stop Mode: Click here
  1. Power Steering ECU Communication Stop Mode: Click here
  1. Television Camera ECU Communication Stop Mode: Click here
  1. Center Airbag sensor Communication Stop Mode: Click here

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