Dtc U0100 Lost Communication With Ecm / Pcm A


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


Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.A750F Automatic Transmission Transaxle.Automatic Transmission System (For 1Kd-Ftv). 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.
    1. for LHD with Entry and Start System: LandCruiser RM000000WIB0ECX.html
    1. for LHD without Entry and Start System: LandCruiser RM000000WIB0EDX.html
    1. for RHD with Entry and Start System: LandCruiser RM000000WIB0EEX.html
    1. for RHD without Entry and Start System: LandCruiser RM000000WIB0EFX.html
1.CHECK HARNESS AND CONNECTOR (ECM - TCM)

  1. Disconnect the C92 ECM connector.

  1. Disconnect the G70 TCM connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    C92-24 (CAN+) - G70-21 (CAN+)
    		Always
    		Below 1 Ω
    C92-18 (CAN-) - G70-20 (CAN-)
    		Always
    		Below 1 Ω
    C92-24 (CAN+) or G70-21 (CAN+) - Body ground or other terminals
    		Always
    		10 kΩ or higher
    C92-18 (CAN-) or G70-20 (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 / DTC / Clear.

  1. Replace the TCM (LandCruiser RM0000048F300JX.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 / DTC.

  1. Read the DTCs using the intelligent tester.

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


B
REPLACE TCM (LandCruiser RM0000048F300JX.html)
A

REPLACE ECM (LandCruiser RM0000013Z002CX.html)