U0101

2AR-FE ENGINE CONTROL: SFI SYSTEM: U0101: Lost Communication with TCM
U0101 - Lost Communication with TCM

DESCRIPTION

The ECM (engine control unit) communicates with the TCM (transmission control ECU) through the Controller Area Network (CAN).

If there is a problem with this communication, the ECM stores a DTC.





MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





CONFIRMATION DRIVING PATTERN

1. Connect the Techstream to the DLC3.

2. Turn the ignition switch to ON and turn the Techstream on.

3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) DTC Check / Clear.

4. Turn the ignition switch off and wait for at least 30 seconds.

5. Turn the ignition switch to ON and turn the Techstream on.

6. Wait 5 seconds or more.

7. Enter the following menus: Powertrain / Engine / Trouble Codes.

8. Read the DTCs.

HINT
* If a DTC is output, the system is malfunctioning.
* If a 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 NORMAL, the system is normal.
* If the judgment result shows ABNORMAL, the system has a malfunction.

12. If the judgment result is INCOMPLETE or UNKNOWN and no DTC is output, perform a universal trip and check for permanent DTCs DTC Check / Clear.

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

PROCEDURE

1. CHECK FOR 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 the DTCs.

Result





HINT
If any DTCs other than U0101 are output, troubleshoot those DTCs first.

B -- GO TO DTC CHART Engine Control - SFI System
A -- Continue to next step.

2. INSPECT TCM (POWER SOURCE)

(a) Disconnect the TCM connector.





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

Standard Resistance:





(c) Turn the ignition switch to ON.

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

Standard Voltage:





Text in Illustration





NG -- GO TO TCM POWER SOURCE CIRCUIT ECU Power Source Circuit
OK -- Continue to next step.

3. 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):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. REPLACE ECM

(a) Replace the ECM Removal.

NEXT -- Continue to next step.

5. CHECK WHETHER DTC OUTPUT RECURS (DTC U0101)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON and turn the Techstream on.

(c) Clear the DTCs DTC Check / Clear.

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

(e) Read the DTCs.

Result





B -- REPLACE TCM Removal

A -- END