CAN COMMUNICATION SYSTEM DIAGNOSIS SYSTEM


  1. ECUS OR SENSORS WHICH COMMUNICATE THROUGH CAN COMMUNICATION SYSTEM


    1. CAN No. 1 Bus


      1. ECM

      2. Main body ECU (Multiplex network body ECU)

      3. Combination meter

      4. Power steering ECU

      5. Center airbag sensor assembly

      6. Skid control ECU (Brake actuator assembly)

      7. Steering angle sensor

      8. Yaw rate sensor

      9. Certification ECU (Smart key ECU)

      10. Power management control ECU

      11. Multi-media module receiver assembly*1

      12. Radio receiver assembly*2

    2. CAN No. 2 Bus


      1. Power management control ECU

      2. AFS ECU (Headlight swivel ECU)*3*4

      3. 4WD control ECU*5

      4. Suspension control ECU*6

      5. Driving support ECU assembly*7

      6. Seat belt control ECU*8

      7. Parking assist ECU*9

      8. Clearance warning ECU*10

    3. CAN MS Bus


      1. Main body ECU (Multiplex network body ECU)

      2. Tilt and telescopic ECU (Multiplex tilt and telescopic ECU)

      3. Outer mirror control ECU RH*11

      4. Outer mirror control ECU LH*11

      5. Position control ECU RH*11

      6. Position control ECU LH*11

      7. Power back door ECU (Back door motor unit)*12

    4. Power Management Bus


      1. Air conditioning amplifier

    5. Sensor Bus*7


      1. Driving support ECU assembly

      2. Millimeter wave radar sensor assembly

        Tech Tips

        *1: w/ Navigation system

        *2: w/ Audio and visual system (w/ Multi-display)

        *3: w/ Automatic headlight beam level control system

        *4: w/ AFS (Adaptive front-lighting system)

        *5: for AWD

        *6: w/ Air suspension system

        *7: w/ Dynamic radar cruise control system

        *8: w/ Pre-crash safety system

        *9: w/ Parking assist monitor system (w/ side monitor system)

        *10: w/ LEXUS parking assist-sensor system (w/o side monitor system)

        *11: w/ Position memory system

        *12: w/ Power back door system

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


    1. The systems (ECUs and sensors) that adopt CAN communication vary depending on the vehicle and optional equipment. Check which systems (ECUs and sensors) are installed on the vehicle.

      ECU/Sensor Name Intelligent Tester Display Applicability
      ECM

      • Engine

      • ECT

      		 Installed on all vehicles
      Main body ECU Main Body Installed on all vehicles
      Combination meter Combination Meter Installed on all vehicles
      Power steering ECU EPS Installed on all vehicles
      Air conditioning amplifier Air Conditioner Installed on all vehicles
      Center airbag sensor assembly SRS Airbag Installed on all vehicles
      Skid control ECU ABS/VSC/TRC Installed on all vehicles
      Steering angle sensor Steering Angle Sensor Installed on all vehicles
      Yaw rate sensor Yaw Rate/Deceleration Sensor Installed on all vehicles
      Certification ECU Smart Access/Wireless Tuner Installed on all vehicles
      Power management control ECU

      • Electric Power Control

      • Power Management1

      • Power Management2

      		 Installed on all vehicles
      Multiplex tilt and telescopic ECU Tilt and Telescopic Installed on all vehicles
      AFS ECU AFS/HL AutoLeveling w/ Automatic headlight beam level control system or AFS (Adaptive front-lighting system)
      Multi-media module receiver assembly AVN1 w/ Navigation system
      Radio receiver assembly AVN1 w/ Audio and visual system (w/ Multi-display)
      4WD control ECU Four Wheel Drive Control AWD vehicles
      Suspension control ECU Air Suspension/AHC/EMS1 w/ Air suspension
      Driving support ECU assembly Cruise Control (ACC) w/ Dynamic radar cruise control system
      Seat belt control ECU Pre-crash Seat Belt1 w/ Pre-crash safety system
      Parking assist ECU

      • Parking Assist Monitor

      • Clearance sonar1*

      w/ Parking assist monitor system (w/ side monitor system)

      (*: w/ parking assist monitor and LEXUS parking assist-sensor system)
      Clearance warning ECU Clearance sonar1 w/ LEXUS parking assist-sensor system (w/o side monitor system)
      Outer mirror control ECU RH Mirror R w/ Position memory system
      Outer mirror control ECU LH Mirror L w/ Position memory system
      Position control ECU RH D-Seat w/ Position memory system
      Position control ECU LH P-Seat w/ Position memory system
      Power back door ECU Power Back Door w/ Power back door system
      Millimeter wave radar sensor assembly - w/ Dynamic radar cruise control system

  3. BUS CHECK (COMMUNICATION MALFUNCTION DTC)

    Tech Tips

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


    1. A019PGX

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

    2. A019NE0

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

    3. A019LO7

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

  4. BUS CHECK (COMMUNICATION BUS CHECK)

    Tech Tips

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


    1. A019NE0

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

    2. A019M6O

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

      Tech Tips

      If any properly connected ECUs or sensors are not displayed, there is a communication stop in the system.

    3. A019O4O

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

  5. DTC TABLE BY ECU

    Tech Tips


    • In the CAN communication system, CAN communication system DTCs can be displayed by the ECU using the intelligent tester.

    • 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.


    1. ECM / Intelligent Tester Display "Engine" (for 2GR-FE)

      DTC Code Detection Item
      U0100*2 Lost Communication with ECM/PCM "A"
      U0101*1 Lost Communication with TCM
      U0122*2 Lost Communication with Vehicle Dynamics Control Module
      U0123*2 Lost Communication with Yaw Rate Sensor Module
      U0126*2 Lost Communication with Steering Angle Sensor Module
      U0235*2 Lost Communication with Cruise Control Front Distance Range Sensor
      U1104 Lost Communication with Driving Support ECU

      Tech Tips


      • DTC communication uses the CAN communication system.

      • *1: Refer to SFI System Click here.

      • *2: Dynamic radar cruise control system DTC

    2. ECM / Intelligent Tester Display "Engine" (for 1AR-FE)

      DTC Code Detection Item
      U0101*4 Lost Communication with TCM

      Tech Tips


      • DTC communication uses the CAN communication system.

      • *4: Refer to SFI System Click here.

    3. TCM / Intelligent Tester Display "ECT"

      DTC Code Detection Item
      U0100*5 Lost Communication with ECM / PCM "A"

      Tech Tips


      • DTC communication uses the CAN communication system.

      • *5: Refer to Automatic Transaxle System Click here for U660F, Click here for U760E).

    4. Main Body ECU (Multiplex Network Body ECU) / Intelligent Tester Display "Main Body"

      DTC Code Detection Item
      U0100 Lost Communication with ECM/ PCM "A"
      U0101 Lost Communication with TCM
      U0151 Lost Communication with Restraints Control Module
      U0155 Lost Communication with Instrument Panel Cluster (IPC)
      U0163 Lost Communication with Navigation Control Module
      U0164 Lost Communication with HVAC Control Module
      U0182 Lost Communication with AFS
      U0199 Lost Communication with "Door Control Module A"
      U0200 Lost Communication with "Door Control Module B"
      U0208 Lost Communication with "Seat Control Module A"
      U0209 Lost Communication with "Seat Control Module B"
      U0230 Lost Communication with Rear Gate Module
      U0327 Software Incompatibility with Vehicle Security Control Module
      U1002 Lost Communication with Gateway Module
      U1110 Lost Communication with Clearance Sonar Module
      U1115 Lost Communication with Tilt and Telescopic Module
      U1126 Lost Communication with Parking Assist Monitor Module
      U1133 Lost Communication with PMN Module

      Tech Tips

      DTC communication uses the CAN communication system.

    5. Combination Meter / Intelligent Tester Display "Combination Meter"

      DTC Code Detection Item
      U0100 Lost Communication with ECM / PCM "A"
      U0129 Lost Communication with Skid Control ECU
      U0131 Lost Communication with Power Steering Control Module
      U0142 Lost Communication with Main Body ECU
      U0151 Lost Communication with Airbag ECU

      Tech Tips

      DTC communication uses the CAN communication system.

    6. Power Steering ECU / Intelligent Tester Display "EMPS"

      DTC Code Detection Item
      U0100 Lost Communication with ECM / PCM "A"
      U0129 Lost Communication with Brake System Control Module
      U1104 Lost Communication with Driving Support ECU

      Tech Tips

      DTC communication uses the CAN communication system.

    7. Center Airbag Sensor Assembly / Intelligent Tester Display "SRS Airbag"

      Tech Tips

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

    8. Skid control ECU (Brake Actuator) / Intelligent Tester Display "ABS/VSC/TRC"

      DTC Code Detection Item
      U0073 Control Module Communication Bus OFF
      U0100 Lost Communication with ECM / PCM
      U0123 Lost Communication with Yaw Rate Sensor Module
      U0124 Lost Communication with Lateral Acceleration Sensor Module
      U0126 Lost Communication with Steering Angle Sensor Module

      Tech Tips

      DTC communication uses the CAN communication system.

    9. Steering Angle Sensor / Intelligent Tester Display "Steering Angle Sensor"

      Tech Tips

      The steering angle sensor is connected to the CAN communication system, but CAN communication DTCs are not output.

    10. Yaw Rate Sensor / Intelligent Tester Display "Yaw Rate / Deceleration Sensor"

      Tech Tips

      The yaw rate sensor is connected to the CAN communication system, but CAN communication DTCs are not output.

    11. Certification ECU / Intelligent Tester Display "Entry&Start"

      DTC Code Detection Item
      U0100 Lost Communication with ECM / PCM "A"
      U0142 Lost Communication with Body Control Module "B"
      U0155 Lost Communication with Instrument Panel Cluster (IPC) Control Module

      Tech Tips

      DTC communication uses the CAN communication system.

    12. Multi-media Module Receiver Assembly / Intelligent Tester Display "Navigation System"

      DTC Code Detection Item
      U0073 Sending Malfunction (Navigation to APGS)
      U0100 Lost Communication with ECM
      U0126 Lost Communication with Steering Angle Sensor Module
      U0129 Lost Communication with Brake System Control Module
      U0140 Lost Communication with Body Control Module
      U0155 Meter ECU Communication
      U1110 Clearance Sonar ECU Communication

      Tech Tips

      DTC communication uses the CAN communication system.

    13. Radio Receiver Assembly / Intelligent Tester Display "Navigation System"

      DTC Code Detection Item
      U0073 Sending Malfunction (Navigation to APGS)
      U0100 Lost Communication with ECM
      U0140 Lost Communication with Body Control Module
      U0155 Meter ECU Communication
      U1110 Clearance Sonar ECU Communication

      Tech Tips

      DTC communication uses the CAN communication system.

    14. Power Management Control ECU / Intelligent Tester Display "Power Source Control"

      DTC Code Detection Item
      U0100 Lost Communication with ECM / PCM
      B2282 Vehicle Speed Signal Malfunction

      Tech Tips


      • DTC communication uses the CAN communication system.

      • "Power Source Control" output DTC is communication error in the CAN No. 1 bus.

    15. Power Management Control ECU / Intelligent Tester Display "Power Management1"

      DTC Code Detection Item
      U0104 Lost Communication with Cruise Control Module
      U0114 Lost Communication with Four-Wheel Drive Clutch Control Module
      U0132 Lost Communication Ride Level Control Module
      U0182 Lost Communication with Lighting Control Module
      U1002 Lost Communication with Gateway Module
      U1100 Lost Communication with Pre-Clash Module
      U1110 Lost Communication with Clearance Sonar Module
      U110B Lost Communication with Parking Assist Control Module "B"

      Tech Tips


      • DTC communication uses the CAN communication system.

      • "Power management1" output DTC is communication error in the CAN No. 2 bus.

    16. Power Management Control ECU / Intelligent Tester Display "Power Management2"

      DTC Code Detection Item
      U0100 Lost Communication with ECM / PCM
      U0164 Lost Communication with HVAC Control Module
      U1002 Lost Communication with Gateway Module

      Tech Tips


      • DTC communication uses the CAN communication system.

      • "Power management2" output DTC is communication error in the power management bus.

    17. Air Conditioning Amplifier / Intelligent Tester Display "Air Conditioner"

      DTC Code Detection Item
      U0100 Lost Communication with ECM
      U0101 Lost Communication with TCM
      U0131 Lost Communication with Electric Power Steering ECU
      U0142 Lost Communication with Main body ECU
      U0155 Lost Communication with Combination Meter

      Tech Tips


      • DTC communication uses the CAN communication system.

      • DTCs can be checked using the air conditioning control panel (DTC 99 is output).

    18. AFS ECU (Headlight swivel ECU) / Intelligent Tester Display "AFS"

      DTC Code Detection Item
      U0073 Control Module Communication Bus OFF
      U0100 Lost Communication with ECM / PCM "A"
      U0101 Lost Communication with ECM
      U0126 Lost Communication with Steering Angle Sensor Module
      U0129 Lost Communication with Skid Control ECU
      U0130 Lost Communication with Steering Effort Control Module
      U0142 Lost Communication with Main Body ECU
      U0163 Lost Communication with Navigation Control Module
      U0182 Lost Communication with AFS ECU
      U1000*6 CAN Communication Failure (Message Registry)
      U1121*7 Lost Communication with Driver Seat Module

      Tech Tips


      • DTC communication uses the CAN communication system.

      • *6: The AFS ECU is malfunctioning if U1000 is output. Refer to the lighting system.

      • *7: Communication error with steering pad switch.

    19. 4WD Control ECU / Intelligent Tester Display "4WD"

      DTC Code Detection Item
      U0073 Control Module Communication Bus OFF
      U0100 Lost Communication with ECM / PCM "A"
      U0126 Lost Communication with Steering Angle Sensor Module
      U0129 Lost Communication with Brake System Control Module

      Tech Tips

      DTC communication uses the CAN communication system.

    20. Suspension Control ECU / Intelligent Tester Display "Air Suspension"

      DTC Code Detection Item
      U0100 Lost Communication with ECM / PCM "A"
      U0101 Lost Communication with TCM
      U0122 Lost Communication with Vehicle Dynamics Control Module
      U0124 Lost Communication with Lateral Acceleration Sensor Module
      U0140 Lost Communication with Main Body ECU
      C1781 Suspension Control ECU Malfunction

      Tech Tips

      DTC communication uses the CAN communication system.

    21. Driving Support ECU / Intelligent Tester Display "Radar Cruise"

      Tech Tips

      Driving support ECU DTCs are output by the ECM.

    22. Driving Support ECU Assembly / Intelligent Tester Display "Pre-crash 2"

      DTC Code Detection Item
      U0122 Lost Communication with Vehicle Dynamics Control Module
      U0123 Lost Communication with Yaw Rate Sensor Module
      U0126 Lost Communication with Steering Angle Sensor Module
      U0235 Lost Communication with Cruise Control Front Distance Range Sensor
      U1002 Lost Communication with Gateway Module
      U1100 Lost Communication with Seat Belt Control ECU

      Tech Tips

      DTC communication uses the CAN communication system.

    23. Millimeter Wave Radar Sensor Assembly

      Tech Tips

      The millimeter wave radar sensor assembly is connected to the CAN communication system, but CAN communication DTCs are not output.

    24. Seat Belt Control ECU / Intelligent Tester Display "Pre-crash"

      DTC Code Detection Item
      U0122 Lost Communication with Vehicle Dynamics Control Module
      U0140 Lost Communication with Main Body ECU
      U0151 Lost Communication with Airbag ECU
      U1104 Lost Communication with Driving Support ECU

      Tech Tips

      DTC communication uses the CAN communication system.

    25. Parking Assist ECU / Intelligent Tester Display "Parking Assist Monitor System"

      DTC Code Detection Item
      U0073 Control Module Communication Bus Off
      U0100 Lost Communication with ECM/PCM "A"
      U0126 Lost Communication with Steering Angle Sensor Module
      U0129 Lost Communication with Brake System Control Module
      U0140 Lost Communication with Main Body ECU
      U1000 ECU Malfunction

      Tech Tips

      DTC communication uses the CAN communication system.

    26. Parking Assist ECU / Intelligent Tester Display "Clearance Sonar"

      DTC Code Detection Item
      U0101 Lost Communication with TCM
      U0142 Lost Communication with Body Control Module "B"
      U0155 Lost Communication with Instrument Panel Cluster Control Module (Combination Meter)

      Tech Tips

      DTC communication uses the CAN communication system.

    27. Clearance Warning ECU / Intelligent Tester Display "Clearance Sonar"

      DTC Code Detection Item
      U0101 Lost Communication with TCM
      U0142 Lost Communication with Body Control Module "B"
      U0155 Lost Communication with Instrument Panel Cluster Control Module (Combination Meter)

      Tech Tips

      DTC communication uses the CAN communication system.

    28. Tilt and Telescopic ECU (Multiplex Tilt and Telescopic ECU) / Intelligent Tester Display "Tilt & Telescopic"

      DTC Code Detection Item
      B2621 Communication Interruption
      B2624 Vehicles Speed Malfunction

      Tech Tips

      DTC communication uses the CAN communication system.

    29. Outer Mirror Control ECU RH / Intelligent Tester Display "Mirror R"

      DTC Code Detection Item
      U0142 Lost Communication with Body Control Module

      Tech Tips

      DTC communication uses the CAN communication system.

    30. Outer Mirror Control ECU LH / Intelligent Tester Display "Mirror L"

      DTC Code Detection Item
      U0142 Lost Communication with Body Control Module

      Tech Tips

      DTC communication uses the CAN communication system.

    31. Position Control ECU RH/ Intelligent Tester Display "D-Seat"

      Tech Tips

      The position control ECU is connected to the CAN communication system, but CAN communication DTCs are not output.

    32. Position Control ECU LH/ Intelligent Tester Display "P-Seat"

      Tech Tips

      The position control ECU is connected to the CAN communication system, but CAN communication DTCs are not output.

    33. Power Back Door ECU (Back Door Motor Unit) / Intelligent Tester Display "Power Back Door"

      Tech Tips

      The back door motor unit (power back door ECU) is connected to the CAN communication system, but CAN communication DTCs are not output.

  6. DTC COMBINATION TABLE


    1. CAN No. 1 Bus

      DTC Trouble Mode
      Output ECU Output DTC ECM Communication Stop Mode Skid Control ECU Communication Stop Mode Steering Angle Sensor Communication Stop Mode Yaw Rate Sensor Communication Stop Mode
      Skid control ECU U0073 X ○*1, 3 X X
      U0100 ○ ○*1 X X
      U0123 X ○*1 X ○
      U0124 X ○*1 X ○
      U0126 X ○*1 ○ X
      Power steering ECU U0100 ○ X X X
      U0129 X ○ X X

      Power management control ECU

      (Electric Power Control)

      		 U0100 ○ X X X
      B2282 X ○ X X
      Combination meter U0100 ○ X X X
      U0129 X ○ X X
      U0131 X X X X
      U0142 X X X X
      U0151 X X X X
      Main body ECU U0100 ○ X X X
      U0101 ○ X X X
      U0151 X X X X
      U0155 X X X X
      U0163 X X X X
      U0327 X X X X
      U1133 X X X X
      Certification ECU U0100 ○ X X X
      U0142 X X X X
      U0155 X X X X
      Multi-media module receiver assembly U0073 X X X X
      U0100 ○ X X X
      U0126 X X ○ X
      U0129 X ○ X X
      U0140 X X X X
      U0155 X X X X
      Radio receiver assembly U0073 X X X X
      U0100 ○ X X X
      U0140 X X X X
      U0155 X X X X
      DTC Trouble Mode
      Output ECU Output DTC Certification ECU Communication Stop Mode Power Steering ECU Communication Stop Mode Power Management Control ECU Communication Stop Mode Center Airbag Sensor Communication Stop Mode
      Skid control ECU U0073 X X X X
      U0100 X X X X
      U0123 X X X X
      U0124 X X X X
      U0126 X X X X
      Power steering ECU U0100 X ○*1 X X
      U0129 X ○*1 X X

      Power management control ECU

      (Electric Power Control)

      		 U0100 X X ○*1 X
      B2282 X X ○*1 X
      Combination meter U0100 X X X X
      U0129 X X X X
      U0131 X ○ X X
      U0142 X X X X
      U0151 X X X ○
      Main body ECU U0100 X X X X
      U0101 X X X X
      U0151 X X X ○
      U0155 X X X X
      U0163 X X X X
      U0327 ○ X X X
      U1133 X X ○ X
      Certification ECU U0100 ○*1 X X X
      U0142 ○*1 X X X
      U0155 ○*1 X X X
      Multi-media module receiver assembly U0073 X X X X
      U0100 X X X X
      U0126 X X X X
      U0129 X X X X
      U0140 X X X X
      U0155 X X X X
      Radio receiver assembly U0073 X X X X
      U0100 X X X X
      U0140 X X X X
      U0155 X X X X
      DTC Trouble Mode
      Output ECU Output DTC Combination Meter ECU Communication Stop Mode Multi-media Module Receiver Assembly Communication Stop Mode Audio Receiver Assembly Communication Stop Mode Main Body ECU Communication Stop Mode
      Skid control ECU U0073 X X X X
      U0100 X X X X
      U0123 X X X X
      U0124 X X X X
      U0126 X X X X
      Power steering ECU U0100 X X X X
      U0129 X X X X

      Power management control ECU

      (Electric Power Control)

      		 U0100 X X X X
      B2282 X X X X
      Combination meter U0100 ○*1 X X X
      U0129 ○*1 X X X
      U0131 ○*1 X X X
      U0142 ○*1 X X ○
      U0151 ○*1 X X X
      Main body ECU U0100 X X X ○*2
      U0101 X X X ○*2
      U0151 X X X ○*2
      U0155 ○ X X ○*2
      U0163 X ○ ○ ○*2
      U0327 X X X ○*2
      U1133 X X X ○*2
      Certification ECU U0100 X X X X
      U0142 X X X ○
      U0155 ○ X X X
      Multi-media module receiver assembly U0073 X ○*1 - X
      U0100 X ○*1 - X
      U0126 X ○*1 - X
      U0129 X ○*1 - X
      U0140 X ○*1 - ○
      U0155 ○ ○*1 - X
      Radio receiver assembly U0073 X - ○*1 X
      U0100 X - ○*1 X
      U0140 X - ○*1 ○
      U0155 ○ - ○*1 X

      Tech Tips


      • ○: Set

      • -: DTC is not output

      • X: Not set or may be set according to the malfunctioning part when one side of the CAN branch wire opens.

      • *1: DTC is not output during communication error, but will be output as a history DTC (past DTC) when communication returns to normal.

      • *2: DTC is not output during communication error.

      • *3: DTC U0100, U0123, U0124 and U0126 are not stored when DTC U0073 has already been stored.

      • Skid Control ECU Communication Stop Mode Click here

      • Power Steering ECU Communication Stop Mode Click here

      • Steering Angle Sensor Communication Stop Mode Click here

      • Yaw Rate Sensor Communication Stop Mode Click here

      • ECM Communication Stop Mode Click here

      • Main Body ECU Communication Stop Mode Click here

      • Combination Meter ECU Communication Stop Mode Click here

      • Center Airbag Sensor Communication Stop Mode Click here

      • Certification ECU Communication Stop Mode Click here

      • Power Management Control ECU Communication Stop Mode Click here

      • Multi-media Module Receiver Assembly Communication Stop Mode Click here

      • Audio Receiver Assembly Communication Stop Mode Click here