SFI SYSTEM, Diagnostic DTC:U1400 and U1401

DTC Code DTC Name
U1400 Alternator Identification Fault or LIN 1 Network: Blocked
U1401 Slave 1 of LIN 1 Network is Confirmed Absent or Communication Lost with the Alternator

DESCRIPTION

The ECM and generator assembly detect reception errors respectively. The generator assembly reception error detected by the generator assembly is sent to the ECM via LIN communication. If an error occurs in the ECM or generator assembly, the ECM determines there is a LIN communication error and stores this DTC.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

U1400

Alternator Identification Fault or LIN 1 Network: Blocked

LIN communication malfunction between ECM and generator assembly.

  • Generator assembly

  • Wire harness or connector

  • ECM

Does not come on

DTC stored

U1401

Slave 1 of LIN 1 Network is Confirmed Absent or Communication Lost with the Alternator

LIN communication malfunction between ECM and generator assembly.

  • Generator assembly

  • Wire harness or connector

  • ECM

Does not come on

DTC stored

WIRING DIAGRAM

A327739E01

PROCEDURE

  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC U1400 OR U1401)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

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

    5. Check for DTCs.

      Result

      Result

      Proceed to

      DTC U1400 or U1401 is output

      A

      DTC U1400 or U1401 and other DTCs are output

      B
      Tip:

      If any DTCs other than U1400 or U1401 are output, troubleshoot those DTCs first.

    B

    GO TO DTC CHART

    A

  2. CHECK HARNESS AND CONNECTOR (GENERATOR ASSEMBLY - ECM)

    1. Disconnect the generator assembly connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      C1-1 (LIN) - A35-38 (LIN)

      Always

      Below 1 Ω

      C1-1 (LIN) or A35-38 (LIN) - Body ground and other terminals

      Ignition switch off

      (while LIN communication is stopped)

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. REPLACE GENERATOR ASSEMBLY

    1. Replace the generator assembly.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

  4. CHECK WHETHER DTC OUTPUT RECURS (DTC U1400 OR U1401)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs.

      Powertrain > Engine > Clear DTCs

    5. Turn the ignition switch off and wait for a few minutes.

    6. Perform the drive test.

    7. Turn the GTS on.

    8. Enter the following menus: Powertrain / Engine / Trouble Codes.

    9. Check for DTCs.

      Powertrain > Engine > Trouble Codes

    Result

    Result

    Proceed to

    DTC U1400 or U1401 is output

    A

    DTCs are not output

    B
    A

    REPLACE ECM

    Click here

    B

    END