CAN COMMUNICATION SYSTEM (for LHD), Diagnostic DTC:U0127

DTC Code DTC Name
U0127 Lost Communication with Tire Pressure Monitor Module

DESCRIPTION

DTC Code DTC Detection Condition Trouble Area
U0127 There is no communication from the tire pressure warning ECU.

  • Power source circuit of tire pressure warning ECU

  • Tire pressure warning ECU CAN branch wire or connector

  • Tire pressure warning ECU

WIRING DIAGRAM

A01ENH0E12

INSPECTION PROCEDURE

Note

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

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. PRECAUTION

    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.


    NEXT

  2. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL


    1. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN 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 SRS system.

      Note

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


    NEXT

  3. CHECK FOR OPEN IN CAN BUS WIRE (TIRE PRESSURE WARNING ECU CAN BRANCH WIRE)


    1. A01EQFRE09
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Tire Pressure Warning ECU)

      Disconnect the L63 tire pressure warning ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      L63-3 (CP1) - L63-6 (CN1) Engine switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE TIRE PRESSURE WARNING ECU CAN BRANCH WIRE OR CONNECTOR (CP1, CN1)

    OK

  4. CHECK HARNESS AND CONNECTOR (TIRE PRESSURE WARNING ECU - BATTERY AND BODY GROUND)


    1. A01EQFRE10
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Tire Pressure Warning ECU)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      L63-1 (IG1) - Body ground Engine switch on (IG) 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L63-7 (GN1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE TIRE PRESSURE WARNING ECU Click here