CAN COMMUNICATION SYSTEM(for LHD) DCM Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
DCM Communication Stop Mode

Either Condition is met:


  • "DCM" is indicated on the "Bus Check" screen Click here

  • Communication system DTCs (DTCs that start with U) that are output correspond to "DCM Communication Stop Mode" in "DTC Combination Table" Click here


  • Telematics transceiver CAN branch wire or connector

  • Power source circuit of telematics transceiver

  • Telematics transceiver ground circuit

  • Telematics transceiver

WIRING DIAGRAM

B002BE0E06

CAUTION / NOTICE / HINT

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

Note


  • 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 (See page ). Click here

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

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the auxiliary battery terminal notice before proceeding with work Click here.

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

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

  • DTC check procedure: Turn the power switch on (IG) and wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.

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

Tech Tips


  • Operating the power switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • 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. CHECK FOR OPEN IN CAN BUS WIRE (TELEMATICS TRANSCEIVER CAN BRANCH WIRE)


    1. B002BHSE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Telematics Transceiver)

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

    2. Disconnect the telematics transceiver connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      N169-15 (CANP) - N169- 16 (CANN) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO TELEMATICS TRANSCEIVER (CANP, CANN)

    OK

  2. CHECK HARNESS AND CONNECTOR (TELEMATICS TRANSCEIVER - BATTERY AND BODY GROUND)


    1. B002BK9E01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Telematics Transceiver)

      Connect the cable to the negative (-) auxiliary battery terminal.

      Note

      When connecting the cable, some systems need to be initialized after the cable is reconnected Click here.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      N169-1 (+B) - Body ground Power switch off 11 to 14 V
      N169-7 (IG2) - Body ground Power switch on (IG) 11 to 14 V
      N169-8 (ACC) - Body ground Power switch on (ACC) 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      N169-4 (E) - Body ground Always Below 1 Ω

    OK

    REPLACE TELEMATICS TRANSCEIVER Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR