AA80E Automatic Transmission

AA80E AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: U0100: Lost Communication with ECM / PCM "A"
U0100 - Lost Communication with ECM / PCM "A"

DESCRIPTION

The ECM communicates with the TCM using the Controller Area Network (CAN).

If there is a problem in this communication, the TCM stores the DTC.





MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Perform the universal trip to clear permanent DTCs AA80E Automatic Transmission System.

HINT
* If CAN communication is malfunctioning, the TCM cannot receive the current data from the ECM. In this case, the freeze frame data output from the TCM is not updated, so the data will not be useful for the inspection. However, reading the Data List as the first step in troubleshooting is an effective way to find malfunctions.
* The malfunctioning area can be checked using the CAN Bus Check function of the Techstream Diagnosis System.

PROCEDURE

1. CHECK DTC OUTPUT (IN ADDITION TO DTC U0100)

(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 / ECT / Trouble Codes.

(e) Read the DTCs using the Techstream.

Result:





HINT
If any other codes besides U0100 are output, perform troubleshooting for those DTCs first.

B -- GO TO DTC CHART Automatic Transmission System - AA80E
A -- Continue to next step.

2. CHECK TCM (POWER SOURCE, BODY GROUND)

(a) Disconnect the A12 and E5 TCM connectors.





(b) Turn the engine switch on (IG).

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

Standard Voltage:





(d) Turn the engine switch off.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (TCM - BATTERY, BODY GROUND)
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (ECM - TCM)

(a) Disconnect the A13 ECM connector.





(b) Disconnect the A12 TCM connector.

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

Standard Resistance:





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

4. CHECK IF DTC RECURS

(a) Clear the DTCs AA80E Automatic Transmission System.

(b) Replace the TCM Removal.

HINT
Replace the TCM with the TCM of a normally functioning vehicle of the same model.

(c) Start the engine.

(d) Read the DTCs.

Result:





B -- REPLACE ECM Removal
A -- Continue to next step.

5. REPLACE TCM

(a) Replace the TCM Removal.

NEXT -- PERFORM A/T CODE REGISTRATION Registration