CAN COMMUNICATION SYSTEM(for LHD with Entry and Start System), Diagnostic DTC:U029D/A2

DTC Code DTC Name
U029D/A2 Lost Communication with NOx Sensor "A"

DESCRIPTION

DTC Code DTC Detection Condition Trouble Area
U029D/A2 There is no communication from the nitrogen oxides sensor.

  • Power source or inside nitrogen oxides sensor

  • Nitrogen oxides sensor CAN branch wire or connector

  • Nitrogen oxides sensor

WIRING DIAGRAM

A01XKC2E04
*a No. 9 Junction Connector
*b from NOx PM Relay
*c Nitrogen Oxides Sensor

CAUTION / NOTICE / HINT

Tech Tips

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

PROCEDURE


  1. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL


    1. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAB main wire and the CAN branch wire.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the airbag system.

      Note


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

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


    NEXT

  2. CHECK FOR OPEN IN CAN BUS WIRE (NITROGEN OXIDES SENSOR CAN BRANCH WIRE)


    1. A01XMGCE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Nitrogen Oxides Sensor)

      Disconnect the nitrogen oxides sensor connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      s6-4 (CAN+) - s6-3 (CAN-) Engine switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE NITROGEN OXIDES SENSOR CAN BRANCH WIRE OR CONNECTOR (CAN+, CAN-)

    OK

  3. CHECK HARNESS AND CONNECTOR (NITROGEN OXIDES SENSOR - BATTERY AND BODY GROUND)


    1. A01XG7JE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Nitrogen Oxides Sensor)

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

      Note

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      s6-2 (GND) - Body ground Always Below 1 Ω

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      s6-1 (BATT) - Body ground Engine switch on (IG) 11 to 14 V

    OK

    REPLACE NITROGEN OXIDES SENSOR Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR