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

      7. Steering angle sensor

      8. Yaw rate sensor

      9. Certification ECU (Smart key ECU)

      10. Power management control ECU

      11. Navigation ECU (Display and navigation module display)*1

    2. CAN No. 2 Bus


      1. Power management control ECU

      2. AFS ECU (Headlight swivel ECU)

      3. Front active stabilizer control ECU*7

      4. Rear active stabilizer control ECU*7

      5. Suspension control ECU*2

      6. Driving support ECU*3

      7. Seat belt control ECU*4

      8. Parking assist ECU*5

      9. Clearance warning ECU*6

    3. CAN No. 3 Bus


      1. Front active stabilizer control ECU*7

      2. Rear active stabilizer control ECU*7

      3. Skid control ECU

    4. 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

      4. Outer mirror control ECU LH

      5. Front power seat switch RH*8

      6. Front power seat switch LH*8

      7. Power back door ECU (Back door motor unit)*9

    5. Power Management Bus


      1. Air conditioning amplifier

      2. Power management control ECU

      3. ECM

      4. Skid control ECU

        Tech Tips

        *1: w/ Navigation system

        *2: w/ Air suspension system

        *3: w/ Dynamic radar cruise control system

        *4: w/ Pre-crash safety system

        *5: w/ Parking assist monitor system

        *6: w/ LEXUS parking assist-sensor system

        *7: w/ Active stabilizer suspension system

        *8: w/ Position memory system

        *9: 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 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 Entry & Start/Wireless Tuner Installed on all vehicles
      Power management ECU

      • Hybrid Control

      • Power Management1

      		 Installed on all vehicles
      AFS ECU AFS/HL AutoLeveling Installed on all vehicles
      Multiplex tilt and telescopic ECU Tilt and Telescopic Installed on all vehicles
      Outer mirror control ECU RH R-Mirror Installed on all vehicles
      Outer mirror control ECU LH L-Mirror Installed on all vehicles
      Display and navigation module display AVN1 w/ Navigation system
      Suspension control ECU Air Suspension/AHC/EMS1 w/ Air suspension
      Driving support ECU 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 System w/ Parking assist monitor system
      Clearance warning ECU Clearance sonar1 w/ LEXUS parking assist-sensor system
      Front power seat switch RH

      • Passenger Seat (for LHD)

      • Driver Seat (for RHD)

      		 w/ Position memory system
      Front power seat switch LH

      • Driver Seat (for LHD)

      • Passenger Seat (for RHD)

      		 w/ Position memory system
      Power back door ECU Power Back Door w/ Power back door system
      Front active stabilizer control ECU Front Active Stabilizer w/ Active stabilizer suspension system
      Rear active stabilizer control ECU Rear Active Stabilizer w/ Active stabilizer suspension 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. A01NEW2

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

    2. A01NHN1

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

    3. A01NHPP

      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. A01NHN1

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

    2. A01ND0M

      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. A01NCO1

      "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 and ECT"

      DTC Code Detection Item
      U0293 Lost Communication with HV ECU

      Tech Tips

      DTC communication uses the CAN communication system.

    2. 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
      U0163 Lost Communication with Navigation Control Module
      U0164 Lost Communication with A/C ECU
      U0182 Lost Communication with AFS ECU
      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
      U0293 Lost Communication with HV ECU
      U0327 Software Incompatibility with Vehicle Security
      U1002 Lost Communication with Gateway Module (Main body ECU)
      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.

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

      DTC Code Detection Item
      U0100 Lost Communication with ECM / PCM "A"
      U0129 Lost Communication with Brake System Control Module
      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.

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

      DTC Code Detection Item
      U0129 Lost Communication with Brake System Control Module

      Tech Tips

      DTC communication uses the CAN communication system.

    5. 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.

    6. Skid control ECU / Intelligent Tester Display "ABS/VSC/TRC"

      DTC Code Detection Item
      U0073 Control Module Communication Bus OFF
      U0123 Lost Communication with Yaw Rate Sensor Module
      U0124 Lost Communication with Lateral Acceleration Sensor Module
      U0126 Lost Communication with Steering Angle Sensor Module
      U0293 Communication Error from HV ECU

      Tech Tips

      DTC communication uses the CAN communication system.

    7. Steering Angle Sensor

      Tech Tips

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

    8. Yaw Rate Sensor

      Tech Tips

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

    9. 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
      U0293 Lost Communication with HV ECU

      Tech Tips

      DTC communication uses the CAN communication system.

    10. Navigation ECU (Display and navigation module display) / Intelligent Tester Display "Navigation System"

      DTC Code Detection Item
      U0073 Control Module Communication Bus Off
      U0155 Lost Communication with Combination Meter
      U0164 Lost Communication with A/C ECU
      U0293 Lost Communication with HV ECU
      U1110 Lost Communication with Clearance Warning ECU

      Tech Tips

      DTC communication uses the CAN communication system.

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

      DTC Code Detection Item
      U0293*1 Lost Communication with HV ECU

      Tech Tips


      • DTC communication uses the CAN communication system.

      • If U0293 is output, Click here.

    12. Power Management Control ECU / Intelligent Tester Display "PM1 Gateway"

      DTC Code Detection Item
      U0132 Lost Communication Ride Level Control Module
      U0182 Lost Communication with Lighting Control Module
      U1002 Lost Communication with Gateway Module
      U1100 Lost Communication with Seat Belt Control ECU
      U1104 Lost Communication with Driving Support ECU
      U1108 Lost Communication with Front Active Stabilizer ECU
      U1109 Lost Communication with Rear Active Stabilizer ECU
      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.

      • "PM1 Gateway" output DTC is communication error in the CAN No. 2 bus.

    13. Power Management Control ECU / Intelligent Tester Display "PM2 Gateway"

      DTC Code Detection Item
      U0100 Lost Communication with ECM / PCM
      U0164 Lost Communication with A/C ECU
      U1002 Lost Communication with Gateway Module
      U0129 Lost Communication with Brake System Control Module

      Tech Tips


      • DTC communication uses the CAN communication system.

      • "PM2 Gateway" output DTC is communication error in the power management bus.

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

      DTC Code Detection Item
      U0100-211 Lost Communication with ECM/PCM "A"
      U0100-212 Lost Communication with ECM/PCM "A"
      U0100-530 Lost Communication with ECM/PCM "A"
      U0122-732*2 Lost Communication with Vehicle Dynamic Control Module
      U0129-220 Lost Communication with Brake System Control Module
      U0129-222 Lost Communication with Brake System Control Module
      U0129-527 Lost Communication with Brake System Control Module
      U0129-528 Lost Communication with Brake System Control Module
      U0140-146 Communication Error from Body ECU to HV ECU
      U0151-763 Communication Error from Airbag ECU to HV ECU
      U0164-594 Lost Communication with A/C ECU
      U0164-827 Lost Communication with A/C ECU
      U1104-728*3 Lost Communication with Driving Support ECU
      U1107-436 Lost Communication with Power Management Module

      Tech Tips


      • DTC communication uses the CAN communication system.

      • *2: Cruise control system DTC

      • *3: Dynamic radar cruise control system DTC

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

      DTC Code Detection Item
      U0100 Communication Malfunction (Engine ECU)
      U0101 Lost Communication with TCM
      U0131 Communication Malfunction (Electric Power Steering ECU)
      U0142 Communication Malfunction (Main body ECU)
      U0155 Communication Malfunction (Meter ECU)
      U0293 Lost Communication with Hybrid Powertrain control Module

      Tech Tips

      DTC communication uses the CAN communication system.

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

      DTC Code Detection Item
      U0073 Control Module Communication Bus OFF
      U0101 Lost Communication with TCM
      U0126 Lost Communication with Steering Angle Sensor Module
      U0129 Lost Communication with Brake System Control Module
      U0142 Lost Communication with Body Control Module
      U0163 Lost Communication with Navigation Control Module
      U0182 Lost Communication with AFS ECU
      U0293 Lost Communication with Hybrid Powertrain control Module
      U1000 CAN Communication Failure (Message Registry)
      U1121 Lost Communication with Driver Seat Module

      Tech Tips

      DTC communication uses the CAN communication system.

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

      DTC Code Detection Item
      U0122 Lost Communication with Vehicle Dynamics Control Module
      U0124 Lost Communication Lateral Acceleration Sensor Module
      U0140 Lost Communication Body Control Module
      U0293 Lost Communication with Hybrid Vehicle Control System Module

      Tech Tips

      DTC communication uses the CAN communication system.

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

      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
      U0293 Lost Communication with Hybrid Vehicle Control System
      U1104*4 Lost Communication with Driving Support ECU

      Tech Tips


      • DTC communication uses the CAN communication system.

      • *4: If U1104 is output, Click here.

    19. Seat Belt Control ECU / Intelligent Tester Display "Pre-crash 1"

      DTC Code Detection Item
      U0140 Lost Communication with J/B ECU
      U0151 Lost Communication with Airbag ECU
      U1104 Lost Communication with Driving Support ECU

      Tech Tips

      DTC communication uses the CAN communication system.

    20. Driving Support ECU / 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*5 Lost Communication with Cruise Control Front Distance Range Sensor
      U0293 Lost Communication with Hybrid Vehicle Control System
      U1100 Lost Communication with Seat Belt Control ECU
      U1104*6 Lost Communication with Driving Support ECU

      Tech Tips


      • DTC communication uses the CAN communication system.

      • *5: If U0235 is output, Click here.

      • *6: If U1104 is output, Click here.

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

      DTC Code Detection Item
      U0073 Control Module Communication Bus Off
      U0126 Lost Communication with Steering Angle Sensor Module
      U0129 Lost Communication with Brake System Control Module
      U0140 Lost Communication with Body Control Module
      U0293 Lost Communication with Hybrid Control Module

      Tech Tips

      DTC communication uses the CAN communication system.

    22. 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 (IPC) Control Module

      Tech Tips

      DTC communication uses the CAN communication system.

    23. Tilt and telescopic ECU (Multiplex Tilt and Telescopic ECU) / Intelligent Tester Display "Tilt and Telescopic"

      Tech Tips

      The multiplex tilt and telescopic ECU is connected to the CAN communication system, but CAN communication DTCs are not output.

    24. 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.

    25. 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.

    26. Front power seat switch LH/ Intelligent Tester Display "Driver Seat" (for LHD), "Passenger Seat" (for RHD)

      Tech Tips

      The front power seat switch LH is connected to the CAN communication system, but CAN communication DTCs are not output.

    27. Front power seat switch RH/ Intelligent Tester Display "Passenger Seat" (for LHD), "Driver Seat" (for RHD)

      Tech Tips

      The front power seat switch RH is connected to the CAN communication system, but CAN communication DTCs are not output.

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

    29. Front Active Stabilizer Control ECU / Intelligent Tester Display "Front Stabilizer"

      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
      U1109 Lost Communication with Rear Active Stabilizer Control ECU
      U0293 Lost Communication with Hybrid Vehicle Control System

      Tech Tips

      DTC communication uses the CAN communication system.

    30. Rear Active Stabilizer Control ECU / Intelligent Tester Display "Rear Stabilizer"

      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
      U1108 Lost Communication with Front Active Stabilizer Control ECU
      U0293 Lost Communication with Hybrid Vehicle Control System

      Tech Tips

      DTC communication uses the CAN communication system.

  6. DTC COMBINATION TABLE


    1. CAN No. 1 Bus

      DTC Trouble Mode (Communication Stop Mode)
      Output ECU Output DTC ECM Skid Control ECU Steering Angle Sensor Yaw Rate Sensor Certification ECU Power Steering ECU
      Skid control ECU U0073 X ○*1, 2 X X X X
      U0123 X ○*1 X ○ X X
      U0124 X ○*1 X ○ X X
      U0126 X ○*1 ○ X X X
      U0293 X ○*1 X X X X
      Power steering ECU U0129 X ○ X X X ○*1

      Power management control ECU

      (Hybrid)

      		 U0100 ○ X X X X X
      U0122 X ○ X X X X
      U0140 X X X X X X
      U0151 X X X X X X
      U1107 X X X X X X
      Combination meter U0100 ○ X X X X X
      U0129 X ○ X X X X
      U0131 X X X X X ○
      U0142 X X X X X X
      U0151 X X X X X X
      Navigation ECU U0073 X X X X X X
      U0155 X X X X X X
      U0164 X X X X X X
      U0293 X X X X X X
      U1110 X X X X X X
      Main body ECU U0100 ○ X X X X X
      U0101 X X X X X X
      U0151 X X X X X X
      U0155 X X X X X X
      U0163 X X X X X X
      U0164 X X X X X X
      U0182 X X X X X X
      U0293 X X X X X X
      U0327 X X X X ○ X
      U1110 X X X X X X
      U1126 X X X X X X
      U1133 X X X X X X
      Certification ECU U0100 ○ X X X ○*1 X
      U0142 X X X X ○*1 X
      U0155 X X X X ○*1 X
      U0293 X X X X ○*1 X
      DTC Trouble Mode (Communication Stop Mode)
      Output ECU Output DTC Power Management ECU Center Airbag Sensor Combination Meter ECU Navigation ECU Main Body ECU
      Skid control U0073 X X X X X
      U0123 X X X X X
      U0124 X X X X X
      U0126 X X X X X
      U0293 ○ X X X X
      Power steering ECU U0129 X X X X X

      Power management control ECU

      (Hybrid)

      		 U0100 ○*1 X X X X
      U0122 ○*1 X X X X
      U0140 ○*1 X X X ○
      U0151 ○*1 ○ X X X
      U1107 ○*1 X X X X

      Power management control ECU

      (Power source control)

      		 U293 ○*1 X X X X
      Combination meter U0100 X X ○*1 X X
      U0129 X X ○*1 X X
      U0131 X X ○*1 X X
      U0142 X X ○*1 X ○
      U0151 X ○ ○*1 X X
      Navigation ECU U0073 X X X ○*1 X
      U0155 X X ○ ○*1 X
      U0164 ○ X X ○*1 ○
      U0293 ○ X X ○*1 X
      U1110 ○ X X ○*1 X
      Main body ECU U0100 X X X X ○*1
      U0101 ○ X X X ○*1
      U0151 X ○ X X ○*1
      U0155 X X ○ X ○*1
      U0163 X X X ○ ○*1
      U0164 ○ X X X ○*1
      U0182 ○ X X X ○*1
      U0293 ○ X X X ○*1
      U0327 X X X X ○*1
      U1110 ○ X X X ○*1
      U1126 ○ X X X ○*1
      U1133 ○ X X X ○*1
      Certification ECU U0100 X X X X X
      U0142 X X X X ○
      U0155 X X ○ X X
      U0293 ○ X X X X

      Tech Tips


      • ○: Set

      • 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 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 ECU Communication Stop Mode Click here

      • Navigation ECU Communication Stop Mode Click here