SFI SYSTEM(w/ Canister Pump Module), Diagnostic DTC:U0101

DTC Code DTC Name
U0101 Lost Communication with TCM

DESCRIPTION

The engine control unit and the transaxle control unit are located inside the ECM. The engine control unit intercommunicates with the transaxle control unit with the Controller Area Network (CAN).

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

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

U0101

Lost Communication with TCM

  • Following conditions are met for 1.25 seconds (1 trip detection logic):

    1. Ignition switch ON

    2. Battery voltage is 10.5 V or higher

    3. No communication between engine control unit and transaxle control unit

ECM

Comes on

DTC stored

MONITOR STRATEGY

Required Sensors/Components

ECM

Frequency of Operation

Continuous

CONFIRMATION DRIVING PATTERN

  1. Connect the GTS to the DLC3.

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

  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

  4. Turn the ignition switch off and wait for at least 30 seconds.

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

  6. Wait 5 seconds or more.

  7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.

  8. Read the pending DTCs.

    Tip:
    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

  9. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

  10. Input the DTC: U0101.

  11. Check the DTC judgment result.

    GTS Display

    Description

    NORMAL

    • DTC judgment completed

    • System normal

    ABNORMAL

    • DTC judgment completed

    • System abnormal

    INCOMPLETE

    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions

    N/A

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU's memory limit

    Tip:
    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

CAUTION / NOTICE / HINT

Tip:

Read freeze frame data using the GTS. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC U0101)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    5. Read the DTCs.

      Powertrain > Engine and ECT > Trouble Codes

    Result

    Result

    Proceed to

    DTC U0101 is output

    A

    DTC U0101 and other DTCs are output

    B

    Tip:

    If any DTCs other than U0101 are output, troubleshoot those DTCs first.

    A

    REPLACE ECM

    B

    GO TO DTC CHART