Dtc U029D/A2 Lost Communication With Nox Sensor A


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL

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

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

DTC 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.
  1. Power source or inside nitrogen oxides sensor
  2. Nitrogen oxides sensor CAN branch wire or connector
  3. Nitrogen oxides sensor
  1. For vehicles with a urea SCR system.

WIRING DIAGRAM


Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Networking.Lin Communication System. Dtc U029D/A2 Lost Communication With Nox Sensor A


INSPECTION PROCEDURE

HINT:
Operating the engine switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.
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.
    NOTICE:
    1. 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 (LandCruiser RM000003YMD00TX.html).
    2. When disconnecting the cable, some systems need to be initialized after the cable is reconnected (LandCruiser RM000003YMF011X.html).

NEXT


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


    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Networking.Lin Communication System. Dtc U029D/A2 Lost Communication With Nox Sensor A

  1. Disconnect the nitrogen oxides sensor connector.

  1. 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
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to Nitrogen Oxides Sensor)


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)


    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Networking.Lin Communication System. Dtc U029D/A2 Lost Communication With Nox Sensor A

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

    NOTICE:
    When disconnecting the cable, some systems need to be initialized after the cable is reconnected (LandCruiser RM000003YMF011X.html).

  1. 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

  1. 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
Text in Illustration
*a
Front view of wire harness connector
(to Nitrogen Oxides Sensor)


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE NITROGEN OXIDES SENSOR (LandCruiser RM000004KGB00NX.html)