U0101
2UR-GSE ENGINE CONTROL: SFI SYSTEM: U0101: Lost Communication with TCM
U0101 - Lost Communication with TCM
DESCRIPTION
The ECM (engine control unit) intercommunicates with the TCM (transmission control ECU) through the Controller Area Network (CAN).
If there is a problem in this intercommunication, the ECM sets a DTC.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
CONFIRMATION DRIVING PATTERN
1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG) and turn the Techstream on.
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Reading and Clearing Diagnostic Trouble Codes.
4. Turn the engine switch off and wait for at least 30 seconds.
5. Turn the engine switch on (IG) and turn the Techstream on.
6. Wait 5 seconds or more.
7. Enter the following menus: Powertrain / Engine / Trouble Codes.
8. Read the pending DTC.
HINT
* If a pending DTC is output, the system is malfunctioning.
* If a pending DTC is not output, perform the following procedure.
9. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
10. Input the DTC: U0101.
11. Check the DTC judgment result.
HINT
* If the judgment result shows ABNORMAL, the system has a malfunction.
* If the judgment result shows NORMAL, the system is normal.
12. If the test result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.
HINT
* If a permanent DTC is output, the system is malfunctioning.
* If no permanent DTC is output, the system is normal.
WIRING DIAGRAM
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 be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
PROCEDURE
1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC U0101)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read the DTCs.
Result:
HINT
If any DTCs other than U0101 are output, troubleshoot those DTCs first.
B -- GO TO DTC CHART SFI System
A -- Continue to next step.
2. INSPECT ECU POWER SOURCE CIRCUIT (TCM POWER SOURCE)
(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:
(d) Reconnect the TCM connector.
NG -- GO TO TCM POWER SOURCE CIRCUIT TCM Power Source Circuit
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (TCM - BODY GROUND)
(a) Disconnect the TCM connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
(c) Reconnect the TCM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (TCM - BODY GROUND)
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (ECM - TCM)
(a) Disconnect the ECM connector.
(b) Disconnect the TCM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
Standard Resistance (Check for Short):
(d) Reconnect the ECM connector and TCM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. REPLACE TCM
(a) Replace the TCM Removal.
NEXT -- Continue to next step.
6. CHECK WHETHER DTC OUTPUT RECURS (DTC U0101)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Turn the engine switch off.
(f) Turn the engine switch on (IG).
(g) Turn the Techstream on.
(h) Wait for 5 seconds or more.
(i) Enter the following menus: Powertrain / Engine / Trouble Codes.
(j) Read the DTCs.
Result:
B -- REPLACE ECM Removal
A -- END