DTC    U1002    Lost Communication with Gateway Module

for Preparation Click here


DESCRIPTION

  1. The power management control ECU* will store this DTC when no signals can be received from the ECUs that have been memorized as those are connected to the power management bus.
  2. 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.

DTC No.
DTC Detection Condition
Trouble Area
U1002
Power management control ECU* cannot receive signals from all ECUs that have been memorized as those connected to the power management bus.
  1. Power management bus circuit
  2. Power source circuit of power management control ECU
  3. ECM main wire or connector
  4. Power management control ECU main wire or connector
  5. ECM
  6. Power management control ECU*
*: for 1KR-FE and 1NR-FE with Entry and Start System

WIRING DIAGRAM


E176121E03


INSPECTION PROCEDURE

NOTICE:
  1. Inspect the fuses for circuit related to this system before performing the following inspection procedure.
  2. Turn the ignition switch off before measuring the resistances of the power management bus wire.
  3. After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not in operation.
  4. 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 doors need to be opened in order to check connectors, open the doors and leave them open.

HINT:
Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

1.CHECK CAN BUS WIRE (ECM - POWER MANAGEMENT CONTROL ECU)


    E170793E01

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D38-12 (CA3P) - D38-11 (CA3N)
    		Ignition switch off
    		54 to 69 Ω

    Result 
    Result
    		Proceed to
    NG
    (70 Ω or higher)
    		A
    NG
    (53 Ω or less)
    		B
    OK
    		C

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D38-12 (CA3P) - D38-1 (AM22) or D38-2 (AM21)
    		Ignition switch off
    		6 kΩ or higher
    D38-11 (CA3N) - D38-1 (AM22) or D38-2 (AM21)
    		Ignition switch off
    		6 kΩ or higher

    Result 
    Result
    		Proceed to
    NG
    		B
    OK
    		C

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D38-12 (CA3P) - D38-5 (GND2) or D38-6 (GND)
    		Ignition switch off
    		200 Ω or higher
    D38-11 (CA3N) - D38-5 (GND2) or D38-6 (GND)
    		Ignition switch off
    		200 Ω or higher

    Text in Illustration 
    *1
    		Compartment with harness connected
    (Power Management Control ECU)
    Result 
    Result
    		Proceed to
    NG
    		B
    OK
    		C



B
Go to step 5

C
Go to step 8
A


2.CHECK FOR OPEN IN CAN BUS WIRE (POWER MANAGEMENT CONTROL ECU)


    E175990E11

  1. Disconnect the D38 power management control ECU connector.

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D38-12 (CA3P) - D38-11 (CA3N)
    		Ignition switch off
    		108 to 132 Ω

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Power Management Control ECU)



NG
Go to step 3
OK

REPLACE POWER MANAGEMENT CONTROL ECU (Click here)  

3.CONNECT CONNECTOR

  1. Reconnect the power management control ECU connector.


NEXT


4.CHECK FOR OPEN IN CAN BUS WIRE (ECM)


    E175986E03

  1. Disconnect the A18 ECM connector.

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A18-4 (CAN+) - A18-5 (CAN-)
    		Ignition switch off
    		108 to 132 Ω

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to ECM)

Result 
Result
Proceed to
NG
A
OK (for 1KR-FE engine)
B
OK (for 1NR-FE engine)
C


B
REPLACE ECM (Click here)

C
REPLACE ECM (Click here)
A

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (CAN-H, CAN-L) 

5.CHECK FOR SHORT IN CAN BUS WIRE (POWER MANAGEMENT CONTROL ECU)


    E170794E01

  1. Disconnect the D38 power management control ECU connector.

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D38-12 (CA3P) - D38-11 (CA3N)
    		Ignition switch off
    		108 to 132 Ω
    D38-12 (CA3P) - D47-16 (BAT)
    		Ignition switch off
    		6 kΩ or higher
    D38-11 (CA3N) - D47-16 (BAT)
    		Ignition switch off
    		6 kΩ or higher
    D38-12 (CA3P) - D47-4 (CG)
    		Ignition switch off
    		200 Ω or higher
    D38-11 (CA3N) - D47-4 (CG)
    		Ignition switch off
    		200 Ω or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Power Management Control ECU)
    *2
    		Front view of DLC3



NG
Go to step 6
OK

REPLACE POWER MANAGEMENT CONTROL ECU (Click here)  

6.CONNECT CONNECTOR

  1. Reconnect the power management control ECU connector.


NEXT


7.CHECK FOR SHORT IN CAN BUS WIRE (ECM)


    E170795E01

  1. Disconnect the A18 ECM connector.

  1. Measure the resistance according to the value(s) in the table blow.

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A18-4 (CAN+) - A18-5 (CAN-)
    		Ignition switch off
    		108 to 132 Ω
    A18-4 (CAN+) - D47-16 (BAT)
    		Ignition switch off
    		6 kΩ or higher
    A18-5 (CAN-) - D47-16 (BAT)
    		Ignition switch off
    		6 kΩ or higher
    A18-4 (CAN+) - D47-4 (CG)
    		Ignition switch off
    		200 Ω or higher
    A18-5 (CAN-) - D47-4 (CG)
    		Ignition switch off
    		200 Ω or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to ECM)
    *2
    		Front view of DLC3

Result 
Result
Proceed to
NG
A
OK (for 1KR-FE engine)
B
OK (for 1NR-FE engine)
C


B
REPLACE ECM (Click here)

C
REPLACE ECM (Click here)
A

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (CAN-H, CAN-L) 

8.CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - BATTERY AND BODY GROUND)


    E175990E12

  1. Disconnect the D38 power management control ECU connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    D38-5 (GND2) - Body ground
    		Always
    		Below 1 Ω
    D38-6 (GND) - Body ground
    		Always
    		Below 1 Ω

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    D38-2 (AM21) - Body ground
    		Always
    		11 to 14 V
    D38-1 (AM22) - Body ground
    		Always
    		11 to 14 V

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Power Management Control ECU)



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE POWER MANAGEMENT CONTROL ECU (Click here)