CAN COMMUNICATION SYSTEM(for LHD), Diagnostic DTC:U0233

DTC Code DTC Name
U0233 Lost Communication with Blind Spot Monitor Master Module

DESCRIPTION

DTC No. Detection Item DTC Detection Condition Trouble Area DTC Output from
U0233 Lost Communication with Blind Spot Monitor Master Module There is no communication from the blind spot monitor sensor LH.
  • Power source circuit of blind spot monitor sensor LH

  • Blind spot monitor sensor LH ground circuit

  • Blind spot monitor sensor LH CAN branch wire or connector

  • Blind spot monitor sensor LH

  • Engine stop and start ECU

Network gateway ECU

For vehicles with a blind spot monitor system.

WIRING DIAGRAM

Figure 1. w/o Stop and Start System

A01XNTME08
*a No. 6 CAN Junction Connector
*b ECU-IG NO.1
*c from IG1 NO.1 Relay
*d Blind Spot Monitor Sensor LH

Figure 2. w/ Stop and Start System

A01XNJME05
*a No. 6 CAN Junction Connector
*b Engine Stop and Start ECU
*c Blind Spot Monitor Sensor LH

CAUTION / NOTICE / HINT

Note


  • Before measuring the resistance of the CAN bus, turn the engine switch off and leave the vehicle for 1 minute or more without operating the key or any switches, or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

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  • Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.

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  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

  • DTC check procedure: Turn the engine switch on (IG) and wait at least 11.68 seconds.

  • After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed.

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  • Inspect the fuses for circuits related to this system before performing the following procedure.

Tech Tips


  • Operating the engine switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.

  • Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE


  1. RECONFIRM DTC OUTPUT


    1. Check for DTCs.


      Body Electrical > Gateway > Trouble Codes

      Tech Tips

      If DTC U1002 is output from the gateway of the network gateway ECU, this indicates a sub bus 2 malfunction. Troubleshoot for DTC U1002 and check for malfunctions in sub bus 2.

      Result
      Result Proceed to
      U1002 is not output from network gateway ECU A
      U1002 is output from network gateway ECU B

    B
    A
  2. CHECK FOR OPEN IN CAN BUS WIRE (BLIND SPOT MONITOR SENSOR LH BRANCH WIRE)


    1. A01XOCUC05
      *a

      Front view of wire harness connector

      (to Blind Spot Monitor Sensor LH)

      Disconnect the cable from the negative (-) battery terminal.

    2. Disconnect the blind spot monitor sensor LH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      V1-2 (CA1P) - V1-7 (CA1N) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Result
      Proceed to
      OK
      NG

    NG
    OK
  3. CHECK HARNESS AND CONNECTOR (BLIND SPOT MONITOR SENSOR LH - BODY GROUND)


    1. A01XOCUC08
      *a

      Front view of wire harness connector

      (to Blind Spot Monitor Sensor LH)

      Reconnect the cable to the negative (-) battery terminal.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      V1-10 (BLGD) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG
    OK
  4. CHECK HARNESS AND CONNECTOR (BLIND SPOT MONITOR SENSOR LH - BATTERY)


    1. A01XOCUC09
      *a

      Front view of wire harness connector

      (to Blind Spot Monitor Sensor LH)

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

      Standard Voltage
      w/o Stop and Start System
      Tester Connection Switch Condition Specified Condition
      V1-5 (BLB) - Body ground Engine switch on (IG) 11 to 14 V
      w/ Stop and Start System
      Tester Connection Switch Condition Specified Condition
      V1-5 (BLB) - Body ground Engine switch on (IG) 10.5 to 16 V
      Result
      Result Proceed to
      OK A
      NG (w/o Stop and Start System) B
      NG (w/ Stop and Start System) C

    A
    B
    C
  5. CHECK HARNESS AND CONNECTOR (BLIND SPOT MONITOR SENSOR LH - ENGINE STOP AND START ECU)


    1. Disconnect the I57 engine stop and start ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      V1-5 (BLB) - I57-12 (IGO1) Always Below 1 Ω
      V1-5 (BLB) or I57-12 (IGO1) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK
    NG