ECD SYSTEM(w/o Glow Plug Controller), Diagnostic DTC:U0129

DTC Code DTC Name
U0129 Lost Communication with Skid Control ECU

DESCRIPTION

The ECM and skid control ECU communicate with each other via CAN communication.

If there is a problem with this communication, the ECM stores this DTC.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

U0129

Lost Communication with Skid Control ECU

All of following conditions met for 1 second or more:

(1 trip detection logic)

  • Ignition switch ON

  • +B terminal voltage 8 V or higher

  • No communication between ECM and skid control ECU

  • Wire harness (CANL and CANH circuits)

  • ECM

  • Skid control ECU

Comes on

DTC stored
Table 1. DTC Detection Drive Pattern

DTC No.

DTC Detection Drive Pattern

U0129

Ignition switch ON

WIRING DIAGRAM

A293661E14

CAUTION / NOTICE / HINT

Tip:

  • When a DTC indicating a CAN communication system malfunction is output, repair the CAN communication system first.

  • Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.

  • If the CAN communication system is malfunctioning, there is no data output from the ECM. In this case, some of the freeze frame data will not be correct and not identical to the ECM data. However the ECM data is correct.

PROCEDURE

  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC U0129)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Enter the following menus: System Select / Health Check.

    4. Read the DTCs.

      Result

      Result

      Proceed to

      DTC U0129 is output

      A

      DTC U0129 and other DTCs are output

      B
      Tip:

      If any DTCs other than U0129 are output, troubleshoot those DTCs first.

    A

    GO TO CAN COMMUNICATION SYSTEM FOR TROUBLESHOOTING

    Click here

    B

    GO TO DTC CHART