Dtc U0101 Lost Communication With Tcm


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

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

INSPECT TCM

CHECK HARNESS AND CONNECTOR (ECM - TCM)

REPLACE ECM

CHECK WHETHER DTC OUTPUT RECURS (DTC U0101)

DTC U0101 Lost Communication with TCM


DESCRIPTION

The ECM (engine control unit) intercommunicates with the TCM (transmission control ECU) through the Controller Area Network (CAN).
If there is a problem in this intercommunication, the ECM sets a DTC.

DTC No.
DTC Detection Condition
Trouble Area
U0101
  1. Following conditions are met for 1.25 seconds (1 trip detection logic):
    1. Ignition switch ON
    2. Battery voltage is 10.5 V or more
    3. No intercommunication between ECM and TCM
  1. ECM
  2. TCM
  3. ECM to TCM circuit

WIRING DIAGRAM


Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.1Kd-Ftv Engine Control System.Ecd System. Dtc U0101 Lost Communication With Tcm


INSPECTION PROCEDURE

NOTICE:
After replacing the ECM, the new ECM needs registration (Toyota Fortuner RM0000012XK030X.html) and initialization (Toyota Fortuner RM0000012X2005X.html).
HINT:
Read freeze frame data using the intelligent tester. Freeze frame data record 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.
1.CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC U0101)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch ON.

  1. Turn the tester ON.

  1. Enter the following menus: Powertrain / Engine / DTC.

  1. Read the DTCs.

    Result:
    Display (DTC output)
    		Proceed to
    U0101
    		A
    U0101 and other DTCs
    		B
    HINT:
    If any DTCs other than U0101 are output, troubleshoot those DTCs first.


B
GO TO DTC CHART (Toyota Fortuner RM000002YV7010X.html)
A


2.INSPECT TCM


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.1Kd-Ftv Engine Control System.Ecd System. Dtc U0101 Lost Communication With Tcm

  1. Disconnect the T17 TCM connector.

  1. Turn the ignition switch ON.

  1. Measure the voltage of the wire harness side connector.

    Standard voltage:
    Tester Connection
    		Specified Condition
    BATT (T17-5) - Body ground
    		11 to 14 V


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.1Kd-Ftv Engine Control System.Ecd System. Dtc U0101 Lost Communication With Tcm

  1. Disconnect the T19 TCM connector.

  1. Measure the resistance of the wire harness side connector.

    Standard resistance:
    Tester Connection
    		Specified Condition
    E1 (T19-1) - Body ground
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.CHECK HARNESS AND CONNECTOR (ECM - TCM)


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.1Kd-Ftv Engine Control System.Ecd System. Dtc U0101 Lost Communication With Tcm

  1. Disconnect the E5 ECM connector.

  1. Disconnect the T17 TCM connector.

  1. Measure the resistance of the wire harness side connector.

    Standard resistance (Check for open):
    Tester Connection
    		Specified Condition
    CAN+ (E5-22) - CAN+ (T17-21)
    		Below 1 Ω
    CAN- (E5-21) - CAN- (T17-20)
    		Below 1 Ω
    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    CAN+ (E5-22) or CAN+ (T17-21) - Body ground
    		10 kΩ or higher
    CAN- (E5-21) or CAN- (T17-20) - Body ground
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.REPLACE ECM

  1. Replace the ECM (Toyota Fortuner RM0000013Z0004X.html).


NEXT


5.CHECK WHETHER DTC OUTPUT RECURS (DTC U0101)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch ON and turn the tester ON.

  1. Enter the following menus: Powertrain / Engine / DTC.

  1. Read the DTCs.

    Result:

    Display (DTC output)
    		Proceed to
    No output
    		A
    U0101
    		B


B
REPLACE TCM
A

END