Dtc U0100 Lost Communication With Ecm / Pcm A

Drivetrain. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25
A750F Automatic Transmission Transaxle. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK HARNESS AND CONNECTOR (ECM - TCM)

CHECK IF DTC OUTPUT RECURS (DTC U0100)

DTC U0100 Lost Communication with ECM / PCM "A"


DESCRIPTION

The ECM communicates with the TCM using the Controller Area Network (CAN).
If there is a problem with this communication, the TCM stores a DTC.

DTC Code
DTC Detection Condition
Trouble Area
U0100
All conditions are met for 1.25 seconds (1-trip detection logic):
  1. Ignition switch is ON.
  2. Battery voltage is 10.5 V or higher.
  3. There is no communication between the ECM and TCM.
  1. Harness or connector
  2. ECM
  3. TCM

WIRING DIAGRAM


Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.A750F Automatic Transmission Transaxle.Automatic Transmission System (For 1Gr-Fe). Dtc U0100 Lost Communication With Ecm / Pcm A


INSPECTION PROCEDURE

HINT:
  1. Refer to the inspection procedure for the CAN communication system.
  2. If the CAN communication malfunctions, the TCM cannot receive current data from the ECM. In this case, the freeze frame data output from the TCM has not been updated so the data will not be useful for the inspection. However, reading the Data List as the first step in troubleshooting is an effective way to find malfunctions.
  3. The malfunctioning area can be confirmed using the Bus Check function of the intelligent tester (HILUX_TGN26 RM000004PEV00AX.html).
1.CHECK HARNESS AND CONNECTOR (ECM - TCM)

  1. Disconnect the G38 ECM connector.

  1. Disconnect the G41 TCM connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    G38-22 (CAN+) - G41-21 (CAN+)
    		Always
    		Below 1 Ω
    G38-21 (CAN-) - G41-20 (CAN-)
    		Always
    		Below 1 Ω
    G38-22 (CAN+) or G41-21 (CAN+) - Body ground or other terminals
    		Always
    		10 kΩ or higher
    G38-21 (CAN-) or G41-20 (CAN-) - Body ground or other terminals
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


2.CHECK IF DTC OUTPUT RECURS (DTC U0100)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the intelligent tester on.

  1. Enter the following menus: Powertrain / ECT / Trouble Codes / Clear.

  1. Replace the TCM (HILUX_TGN26 RM0000048F3005X.html).

    HINT:
    Replace the TCM with the TCM of a normally functioning vehicle of the same model.

  1. Start the engine.

  1. Enter the following menus: Powertrain / ECT / Trouble Codes.

  1. Read the DTCs using the tester.

    Result
    Result
    		Proceed to
    U0100 is output
    		A
    DTCs are not output
    		B


B
REPLACE TCM (HILUX_TGN26 RM0000048F3005X.html)
A

REPLACE ECM (HILUX_TGN26 RM0000013Z001IX.html)