- DTC judgment completed
- System normal
| Last Modified: 05-13-2024 | 6.11:8.1.0 | Doc ID: RM1000000026FM3 |
| Model Year Start: 2023 | Model: Corolla Hatchback | Prod Date Range: [09/2022 - 11/2022] |
| Title: K120 / K121 (CVT): K120 CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM: U010087; Lost Communication with ECM/PCM "A" Missing Message; 2023 MY Corolla Corolla Hatchback [09/2022 - 11/2022] | ||
|
DTC |
U010087 |
Lost Communication with ECM/PCM "A" Missing Message |
DESCRIPTION
The TCM communicates with the ECM via CAN communication.
If a problem occurs in this communication, the TCM stores this DTC.
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
MIL |
Memory |
Note |
|---|---|---|---|---|---|---|
|
U010087 |
Lost Communication with ECM/PCM "A" Missing Message |
No communication between the TCM and ECM for 1.25 seconds or more (1-trip detection logic) |
|
Comes on |
DTC stored |
SAE Code: U0100 |
MONITOR STRATEGY
|
Related DTCs |
U0100: Lost communication with ECM/PCM Verify communication |
|
Required sensors/Components |
ECM |
|
Frequency of Operation |
Continuous |
|
Duration |
1.25 sec. |
|
MIL Operation |
Immediate |
|
Sequence of Operation |
None |
TYPICAL ENABLING CONDITIONS
for TMMMS Made
|
The monitor will run whenever the following DTCs are not stored |
None |
|
Battery voltage (1 sec. or more) |
10.5 V or more |
|
Engine switch |
On (IG) |
|
Starter |
OFF |
for TMC Made
|
The monitor will run whenever the following DTCs are not stored |
None |
|
Battery voltage (1 sec. or more) |
10.5 V or more |
|
Engine switch |
On (IG) |
TYPICAL MALFUNCTION THRESHOLDS
|
Communication signal |
Lost communication with ECM/PCM |
CONFIRMATION DRIVING PATTERN
HINT:
- After repairs have been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
-
When clearing the permanent DTCs, refer to the Clear Permanent DTC procedure.
Click here
![2023 MY Corolla Corolla Hatchback [09/2022 - 11/2022]; K120 / K121 (CVT): K120 CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM: DTC CHECK / CLEAR](/t3Portal/stylegraphics/info.gif)
- Connect the Techstream to the DLC3.
- Turn the engine switch on (IG) and turn the Techstream on.
- Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
- Turn the engine switch off and wait for 3 minutes or more.
- Turn the engine switch on (IG) and turn the Techstream on.
-
Wait for 3 seconds or more with the engine switch on (IG). [*1]
HINT:
[*1]: Normal judgment procedure.
The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
- Enter the following menus: Powertrain / Transmission / Utility / All Readiness.
- Input the DTC: U010087.
-
Check the DTC judgment result.
Techstream Display
Description
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 memory limit
HINT:
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows INCOMPLETE or N/A, perform the normal judgment procedure again.
WIRING DIAGRAM
for TMMMS Made
for TMC Made
CAUTION / NOTICE / HINT
NOTICE:
-
Perform the universal trip to clear permanent DTCs.
Click here
-
Perform registration and/or initialization when parts related to the continuously variable transaxle system are replaced.
Click here
-
Check that no DTCs are stored after performing initialization.
Click here
- Inspect the fuses for circuits related to this system before performing the following inspection procedure.
PROCEDURE
|
1. |
CHECK TERMINAL VOLTAGE (POWER SOURCE OF TCM) |
(a) Disconnect the C80 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 |
Condition |
Specified Condition |
|---|---|---|
|
C80-1 (+B) - C80-2 (E1) |
Engine switch on (IG) |
11 to 14 V |
(d) Turn the engine switch off.
(e) Connect the C80 TCM connector.
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE OF TCM) |
|
|
2. |
CHECK HARNESS AND CONNECTOR (ECM - TCM) |
(a) for TMMMS Made:
(1) Disconnect the A47 ECM connector.
(b) for TMC Made:
(1) Disconnect the C76 ECM connector.
(c) Disconnect the C80 TCM connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance (for TMMMS Made):
|
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 |
Always |
10 kΩ or higher |
|
C80-17 (CAN-) or A47-17 (CANN) - Body ground |
Always |
10 kΩ or higher |
Standard Resistance (for TMC Made):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
C80-18 (CAN+) - C76-40 (CANP) |
Always |
Below 1 Ω |
|
C80-17 (CAN-) - C76-39 (CANN) |
Always |
Below 1 Ω |
|
C80-18 (CAN+) or C76-40 (CANP) - Body ground |
Always |
10 kΩ or higher |
|
C80-17 (CAN-) or C76-39 (CANN) - Body ground |
Always |
10 kΩ or higher |
(e) Connect the C80 TCM connector.
(f) for TMMMS Made:
(1) Connect the A47 ECM connector.
(g) for TMC Made:
(1) Connect the C76 ECM connector.
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - TCM) |
|
|
3. |
REPLACE TCM |
(a) Replace the TCM.
Click here
|
|
4. |
PERFORM REGISTRATION AND INITIALIZATION |
(a) Perform Registration and Initialization.
for Registration: Click here
for Initialization: Click here
|
|
5. |
CHECK DTC OUTPUT (DTC U010087) |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Clear the DTCs.
Powertrain > Transmission > Clear DTCs
(e) Turn the engine switch off and wait for at least 30 seconds.
(f) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(g) Enter the following menus: Powertrain / Transmission / Trouble Codes.
(h) Read the DTCs.
Powertrain > Transmission > Trouble Codes
|
Result |
Proceed to |
|---|---|
|
DTCs are not output |
A |
|
DTC U010087 is output |
B |
| A |
|
END |
|
|
6. |
REPLACE ECM |
(a) Replace the ECM.
Click here
| NEXT |
|
|
|