Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001BGZ8
Model Year Start: 2019 Model: Corolla Hatchback Prod Date Range: [06/2018 - 03/2019]
Title: M20A-FKS (ENGINE CONTROL): SFI SYSTEM: U010187; Lost Communication with TCM Missing Message; 2019 - 2020 MY Corolla Corolla Hatchback [06/2018 - 03/2019]

DTC

U010187

Lost Communication with TCM Missing Message

MONITOR DESCRIPTION

The Transmission Control Module (TCM) and ECM perform 2-way communication with each other via the Controller Area Network (CAN). The TCM sends signals to the ECM concerning required engine speed, required engine torque, warning indicators in the combination meter assembly, DTCs and other data. The ECM sends signals to the TCM concerning engine speed, opening angle of the throttle valve, temperature of intake air, temperature of engine coolant, engine torque and other data. If the TCM cannot communicate with the ECM, the TCM will conclude that there is a malfunction in the CAN communication system, illuminate the MIL and store this DTC.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

Note

U010187

Lost Communication with TCM Missing Message

All of the following conditions are met for 1.25 seconds or more (1 trip detection logic):

  • Engine switch on (IG)
  • Battery voltage is 10 V or higher
  • No communication between engine control unit and transmission control unit
  • ECM to TCM circuit
  • TCM
  • ECM

Comes on

DTC stored

SAE Code: U0101

MONITOR STRATEGY

Related DTCs

U0101: Lost communication with TCM (verify communication)

Required Sensors/Components (Main)

ECM

Required Sensors/Components (Related)

-

Frequency of Operation

Continuous

Duration

1.25 seconds

MIL Operation

Immediate

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever the following DTCs are not stored

None

All of the following conditions are met

-

Battery voltage

10 V or higher

Engine switch

on (IG)

Starter

Off

TYPICAL MALFUNCTION THRESHOLDS

Communication signal

Lost communication with TCM

CONFIRMATION DRIVING PATTERN

HINT:

  • After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

    Click here 2019 - 2022 MY Corolla Corolla Hatchback [06/2018 - 09/2022]; M20A-FKS (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR

  • When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.

    Click here 2019 - 2022 MY Corolla Corolla Hatchback [06/2018 - 09/2022]; M20A-FKS (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR

  1. Connect the Techstream to the DLC3.
  2. Turn the engine switch on (IG).
  3. Turn the Techstream on.
  4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  5. Turn the engine switch off and wait for at least 30 seconds.
  6. Turn the engine switch on (IG).
  7. Turn the Techstream on.
  8. Wait 5 seconds or more [A].
  9. Enter the following menus: Powertrain / Engine / Trouble Codes [B].
  10. Read the DTCs.

    HINT:

    • If a pending DTC is output, the system is malfunctioning.
    • If a pending DTC is not output, perform the following procedure.
  11. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
  12. Input the DTC: U010187.
  13. Check the DTC judgment result.

    Techstream 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

    HINT:

    • If the judgment result is NORMAL, the system is normal.
    • If the judgment result is ABNORMAL, the system has a malfunction.
    • If the judgment result is INCOMPLETE, perform steps [A] through [B] again.
    • [A] to [B]: Normal judgment procedure.

      The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.

    • When clearing the permanent DTCs, do not disconnect the cable from the battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.

HINT:

Read Freeze Frame Data using the Techstream. 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 U010187)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: System Select / Health Check.

(e) Read the DTCs.

Result

Proceed to

DTC U010187 is output

A

DTC U010187 and other DTCs are output

B

HINT:

If any DTCs other than U010187 are output, troubleshoot those DTCs first.

B

GO TO DTC CHART

A

2.

CHECK TERMINAL VOLTAGE (POWER SOURCE OF TCM)

*a

Front view of wire harness connector

(to TCM)

(a) Disconnect the TCM connector.

(b) Turn the engine switch on (IG).

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

C80-1 (+B) - C80-2 (E1)

Engine switch on (IG)

11 to 14 V

C80-41 (IGSW) - C80-2 (E1)

Engine switch on (IG)

11 to 14 V

NG

GO TO TCM POWER SOURCE CIRCUIT

OK

3.

CHECK HARNESS AND CONNECTOR (TCM - ECM)

(a) Disconnect the TCM connector.

(b) Disconnect the ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

C80-18 (CAN+) - A47 -7 (CANP)

Always

Below 1 Ω

C80-17 (CAN-) - A47 -17 (CANN)

Always

Below 1 Ω

C80-18 (CAN+) or A47 -7 (CANP) - Body ground and other terminals

Always

10 kΩ or higher

C80-17 (CAN-) or A47 -17 (CANN) - Body ground and other terminals

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.

REPLACE TCM

(a) Replace the TCM.

Click here 2019 MY Corolla Corolla Hatchback [06/2018 - 01/2019]; K120 / K121 (CVT): K120 TCM: REMOVAL 2020 MY Corolla Corolla Hatchback [01/2019 - 03/2019]; K120 / K121 (CVT): K120 TCM: REMOVAL

NEXT

5.

CLEAR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs.

Powertrain > Engine > Clear DTCs

(e) Turn the engine switch off and wait for at least 30 seconds.

NEXT

6.

CHECK WHETHER DTC OUTPUT RECURS (DTC U010187)

(a) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.

(b) Enter the following menus: Powertrain / Engine / Trouble Codes.

(c) Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

Proceed to

DTCs are not output

A

DTC U010187 is output

B

A

END

B

REPLACE ECM 2019 MY Corolla Corolla Hatchback [06/2018 - 01/2019]; M20A-FKS (ENGINE CONTROL): ECM: REMOVAL 2020 MY Corolla Corolla Hatchback [01/2019 - 03/2019]; M20A-FKS (ENGINE CONTROL): ECM: REMOVAL