- Following conditions are met for 1.25 seconds
-
(1 trip detection logic):
- Ignition switch ON
- Battery voltage 10.5 V or higher
- No intercommunication between ECM and TCM
| Last Modified: 04-05-2023 | 6.11:8.1.0 | Doc ID: RM100000000VIBW |
| Model Year Start: 2016 | Model: Sienna | Prod Date Range: [12/2015 - 08/2016] |
| Title: 2GR-FE (ENGINE CONTROL): SFI SYSTEM: U0101; Lost Communication with TCM; 2016 MY Sienna [12/2015 - 08/2016] | ||
|
DTC |
U0101 |
Lost Communication with TCM |
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 system, illuminate the MIL and store a DTC.
|
DTC No. |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
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 |
Immediately |
|
Sequence of Operation |
None |
TYPICAL ENABLING CONDITIONS
|
Monitor runs whenever following DTCs are not present |
None |
|
Battery voltage |
10.5 V or higher (More than 1 second) |
|
Ignition switch |
ON |
|
Starter |
OFF |
TYPICAL MALFUNCTION THRESHOLDS
|
Communication signal |
Lost communication with TCM |
CONFIRMATION DRIVING PATTERN
- Connect the Techstream to the DLC3.
- Turn the ignition switch to ON and turn the Techstream on.
-
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) (See page
![2016 MY Sienna [12/2015 - 08/2016]; 2GR-FE (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR](/t3Portal/stylegraphics/info.gif)
).
- Turn the ignition switch off and wait for at least 30 seconds.
- Turn the ignition switch to ON and turn the Techstream on.
- Wait 5 seconds or more.
- Enter the following menus: Powertrain / Engine / Trouble Codes.
-
Read pending DTCs.
HINT:
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
- Enter the following menus: Powertrain / Engine / Utility / All Readiness.
- Input the DTC: U0101.
-
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
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 ABNORMAL, the system has a malfunction.
-
If the result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs (See page
).
HINT:
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection 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 U0101) |
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read DTCs.
Result
|
Result |
Proceed to |
|---|---|
|
DTC U0101 is output |
A |
|
DTC U0101 and other DTCs are output |
B |
HINT:
If any DTCs other than U0101 are output, troubleshoot those DTCs first.
| B |
|
|
|
2. |
INSPECT ECU POWER SOURCE CIRCUIT (TCM POWER SOURCE) |
|
(a) Disconnect the TCM connector. |
|
(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
B2-1 (BATT) - B2-8 (E1) |
Always |
11 to 14 V |
|
B2-18 (+B) - B2-8 (E1) |
Ignition switch ON |
11 to 14 V |
Text in Illustration
|
*a |
Front view of wire harness connector (to TCM) |
| NG |
|
GO TO TCM POWER SOURCE CIRCUIT |
|
|
3. |
CHECK HARNESS AND CONNECTOR (ECM - TCM) |
(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 (Check for Open):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
B2-6 (CAN+) - B1-24 (CAN+) |
Always |
Below 1 Ω |
|
B2-7 (CAN-) - B1-1 (CAN-) |
Always |
Below 1 Ω |
Standard Resistance (Check for Short):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
B2-6 (CAN+) or B1-24 (CAN+) - Body ground |
Always |
10 kΩ or higher |
|
B2-7 (CAN-) or B1-1 (CAN-) - Body ground |
Always |
10 kΩ or higher |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
4. |
REPLACE ECM |
(a) Replace the ECM (See page
).
|
|
5. |
CHECK WHETHER DTC OUTPUT RECURS (DTC U0101) |
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read DTCs.
Result
|
Result |
Proceed to |
|---|---|
|
DTC is not output |
A |
|
DTC U0101 is output (for 2WD) |
B |
|
DTC U0101 is output (for AWD) |
C |
| A |
|
END |
| B |
|
| C |
|
|
|