Engine Control System - SFI System (from 12/2010)

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

DESCRIPTION

The Transmission Control Module (TCM) and ECM perform 2-way communications with each other via the Controller Area Network (CAN). The TCM sends signals to the ECM concerning required engine rpm, required engine torques, warning indicators in the combination meter assembly, DTCs and other data. The ECM sends signals to the TCM concerning engine rpm, opening angles of the throttle valve, temperature of intake air, temperature of engine coolant, engine torques 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 set 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 (from 12/2010).

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

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

6. Wait 5 seconds or more.

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

8. Read the DTCs [B].

9. If a DTC is output, the system is malfunctioning.

HINT
If a DTC is not output, perform the following procedure.

10. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

11. Input the DTC: U0101.

12. Check the DTC judgment result [B].





HINT
* If the judgment result shows ABNORMAL, the system has a malfunction.
* If the judgment result shows NORMAL, the system is normal.
* If the judgment result shows INCOMPLETE or UNKNOWN, perform step [A] again.

13. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

14. Check the judgment result.

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

15. If the test result is INCOMPLETE or UNKNOWN and no DTC is output, perform a universal trip and check for permanent DTCs DTC Check / Clear (from 12/2010).

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 OTHER DTC 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 is output, troubleshoot those DTCs first.

B -- GO TO DTC CHART Diagnostic Trouble Code Chart (from 12/2010)
A -- Continue to next step.

2. CHECK TCM TERMINAL VOLTAGE (+B AND E1 TERMINALS)

(a) Disconnect the TCM connector.





(b) Turn the ignition switch to ON.

(c) Measure the voltage of the TCM connectors.

Standard Voltage:





(d) Turn the ignition switch off.

(e) Measure the resistance of the TCM connector.

Standard Resistance:





(f) Reconnect the TCM connector.

NG -- GO TO TCM POWER SOURCE CIRCUIT
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (ECM - TCM)

(a) Disconnect the TCM connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance of the wire harness side connectors.

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(d) Reconnect the TCM connector.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - TCM)
OK -- Continue to next step.

4. REPLACE ECM

(a) Replace the ECM Removal (from 12/2010).

NOTICE:
Replace the ECM with a ECM from a normally functioning vehicle of the same model.

NEXT -- Continue to next step.

5. CHECK IF DTC RECURS

(a) Connect Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Clear the DTCs DTC Check / Clear (from 12/2010).

(e) Turn the ignition switch off.

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

(g) Wait 5 seconds or more.

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

(i) Read the DTCs.

Result:





B -- REPLACE TCM

A -- END