Lost Communication With ECM / PCM "A" - CAN Communication System

NETWORKING: CAN COMMUNICATION SYSTEM: U1002, U0100: Lost Communication with Gateway Module (Power Management2)
U0100 - Lost Communication with ECM / PCM "A"

DESCRIPTION

* The power management control ECU will store this DTC when no signals can be received from the ECUs that have been memorized as those that are connected to the power management bus.

* When the power management control ECU receives a response signal from the ECUs connected to the power management bus, the power management control ECU recognizes and memorizes that the ECU is connected to the power management bus. Based on this memorized data, the power management control ECU monitors for malfunctions in the ECUs connected to the power management bus when communicating with those ECUs. If the power management control ECU cannot receive response signals from the ECUs that have been memorized as those connected to the power management bus, the power management control ECU determines that a malfunction exists.

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:
* Turn the ignition switch off before measuring the resistances between CAN bus main wires and between CAN bus branch wires.
* Turn the ignition switch off before inspecting CAN bus wires for a ground short.
* After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.
* Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.

HINT
* Operating the ignition switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
* Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE

1. CHECK CAN BUS WIRE

(a) Turn the ignition switch off.

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

Standard Resistance:

Text in Illustration

(c) Disconnect the cable from the negative (-) battery terminal.

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

Standard Resistance:

NG -- CHECK CAN MAIN WIRE (POWER MANAGEMENT CONTROL ECU)
OK -- Continue to next step.

2. CHECK DTC OUTPUT

(a) Check the DTC.

HINT
If the SFI system or charging system DTC is output, troubleshoot and check for malfunctions in the EFI and charging system.

NG -- GO TO DTC CHART
OK -- Continue to next step.

3. REPLACE POWER MANAGEMENT CONTROL ECU

(a) Replace the power management control ECU Removal.

NEXT -- Continue to next step.

4. RECONFIRM DTC OUTPUT

(a) Reconfirm the DTC output from power management control ECU (power management2).

OK:

DTC U1002 is not output.

NG -- REPLACE ECM Removal

OK -- END

5. CHECK CAN MAIN WIRE (POWER MANAGEMENT CONTROL ECU)

(a) Disconnect the power management control ECU connector.

Text in Illustration

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

Standard Resistance:

HINT
It is only necessary to perform the inspection in the above table for the result (open or short circuit) that was obtained in the Check CAN Bus Wire inspection.

Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.

NG -- CHECK FOR CAN MAIN WIRE (ECM)

OK -- REPLACE POWER MANAGEMENT CONTROL ECU

6. CHECK FOR CAN MAIN WIRE (ECM)

(a) Reconnect the power management control ECU connector.

(b) for 1AR-FE engine:

(1) Disconnect the ECM connectors.

Text in Illustration

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

Standard Resistance:

Text in Illustration

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

Standard Resistance:

C -- CHECK FOR SHORT IN CAN MS BUS WIRE (CAN NO. 1 JUNCTION CONNECTOR - ECM)

B -- REPLACE ECM Removal

A -- REPLACE ECM Removal

7. CHECK FOR SHORT IN CAN MS BUS WIRE (CAN NO. 1 JUNCTION CONNECTOR - ECM)

(a) Reconnect the ECM connectors.

(b) Disconnect the CAN No. 1 junction connector (A44).

Text in Illustration

HINT
It is only necessary to perform the inspection in the above table for the result (open or short circuit) that was obtained in the Check CAN Bus Wire inspection.

Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.

NG -- REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 JUNCTION CONNECTOR - ECM)
OK -- Continue to next step.

8. CHECK FOR SHORT IN CAN MS BUS MAIN WIRE (CAN NO. 1 JUNCTION CONNECTOR - POWER MANAGEMENT CONTROL ECU)

(a) Disconnect the CAN No. 1 junction connector (D56).

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

Standard Resistance:

Text in Illustration

HINT
It is only necessary to perform the inspection in the above table for the result (open or short circuit) that was obtained in the Check CAN Bus Wire inspection.

Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.

NG -- REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 JUNCTION CONNECTOR - POWER MANAGEMENT CONTROL ECU)

OK -- REPLACE CAN NO. 1 JUNCTION CONNECTOR