CAN COMMUNICATION SYSTEM, Diagnostic DTC:U1002, U0073
| DTC Code | DTC Name |
|---|---|
| U1002 | Lost Communication with Gateway Module (Power Management1) |
| U0073 | Control Module Communication Bus Off |
DESCRIPTION
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The power management control ECU stores these DTCs when no signals can be received from the ECUs that have been memorized as those connected to the V2 bus.
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When the power management control ECU receives a response signal from an ECU connected to the V2 bus, the power management control ECU recognizes and memorizes that the ECU is connected to the V2 bus. Based on this memorized data, the power management control ECU monitors for malfunctions in the ECUs connected to the V2 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 V2 bus, the power management control ECU determines that a malfunction exists.
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If 2 or more DTCs are output during the DTC check, one side of the CAN branch wire may be open (one side of the CANH [CAN branch wire]/CANL [CAN branch wire] of the ECU and/or sensor is open).
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| U1002 | Lost communication with the gateway module (Power Management1). |
|
| U0073 | Control module communication bus is off. |
|
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*1: w/ Adaptive Front-lighting System
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*2: w/o Adaptive Front-lighting System
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For vehicles with an entry and start system.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
Note
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
Tech Tips
Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.
PROCEDURE
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PRECAUTION
Note
After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work Click here.
NEXT 
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DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL
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Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.
CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.
Note
When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.
NEXT
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CHECK CAN BUS WIRE (CHECK MAIN WIRE FOR DISCONNECTION, CHECK BUS LINE FOR SHORT CIRCUIT)
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Text in Illustration *a Component with harness connected
(Power Management Control ECU)
Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Switch Condition Specified Condition Resistance: Malfunction D111-26 (CA2H) - D111-25 (CA2L) Ignition switch off 54 to 69 Ω Below 54 Ω: Short in line D111-26 (CA2H) - D111-25 (CA2L) Ignition switch off 54 to 69 Ω Higher than 69 Ω: Open in CAN main bus line D111-26 (CA2H) - D111-2 (AM21) Ignition switch off 6 kΩ or higher Below 6 kΩ: +B short D111-25 (CA2L) - D111-2 (AM21) Ignition switch off 6 kΩ or higher Below 6 kΩ: +B short D111-26 (CA2H) - D111-6 (GND) Ignition switch off 200 Ω or higher Below 200 Ω: Ground short D111-25 (CA2L) - D111-6 (GND) Ignition switch off 200 Ω or higher Below 200 Ω: Ground short Result Result Proceed to NG
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Open in CAN main bus line
A NG
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Short in line
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+B short
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GND short
B OK C -
B 
CHECK FOR SHORT IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - HEADLIGHT ECU) Click here
C
CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - BATTERY AND BODY GROUND) Click here
A
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CHECK FOR OPEN IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - POWER MANAGEMENT CONTROL ECU)
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Text in Illustration *a Rear view of wire harness connector
(to CAN Junction Connector)
Disconnect the CAN junction connector.
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Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Switch Condition Specified Condition D93-1 (CANH) - D93-2 (CANL) Ignition switch off 108 to 132 Ω
OK 
REPLACE CAN JUNCTION CONNECTOR
NG
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CONNECT CONNECTOR
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Reconnect the D93 CAN junction connector.
NEXT
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CHECK FOR OPEN IN CAN BUS WIRE (POWER MANAGEMENT CONTROL ECU - CAN JUNCTION CONNECTOR)
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Text in Illustration *a Rear view of wire harness connector
(to Power Management Control ECU)
Disconnect the power management control ECU connector.
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Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Switch Condition Specified Condition D111-26 (CA2H) - D111-25 (CA2L) Ignition switch off 108 to 132 Ω
OK
REPLACE POWER MANAGEMENT CONTROL ECU Click here
NG
REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO POWER MANAGEMENT CONTROL ECU (POWER MANAGEMENT CONTROL ECU - CAN JUNCTION CONNECTOR)
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CHECK FOR SHORT IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - HEADLIGHT ECU)
Note
For vehicles without an LED headlight, go to "Check for Short in CAN Bus Wire (CAN Junction Connector - Power Management Control ECU)".
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Text in Illustration *a Rear view of wire harness connector
(to CAN Junction Connector)
*b Front view of DLC3 Disconnect the CAN junction connector.
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Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Switch Condition Specified Condition D95-1 (CANH) - D95-2 (CANL) Ignition switch off 200 Ω or higher D95-1 (CANH) - D8-4 (CG) Ignition switch off 200 Ω or higher D95-2 (CANL) - D8-4 (CG) Ignition switch off 200 Ω or higher D95-1 (CANH) - D8-16 (BAT) Ignition switch off 6 kΩ or higher D95-2 (CANL) - D8-16 (BAT) Ignition switch off 6 kΩ or higher
NG
CONNECT CONNECTOR Click here
OK
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CHECK FOR SHORT IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - POWER MANAGEMENT CONTROL ECU)
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Text in Illustration *a Rear view of wire harness connector
(to CAN Junction Connector)
*b Front view of DLC3 Disconnect the CAN junction connector.
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Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Switch Condition Specified Condition D93-1 (CANH) - D93-2 (CANL) Ignition switch off 108 to 132 Ω D93-1 (CANH) - D8-4 (CG) Ignition switch off 200 Ω or higher D93-2 (CANL) - D8-4 (CG) Ignition switch off 200 Ω or higher D93-1 (CANH) - D8-16 (BAT) Ignition switch off 6 kΩ or higher D93-2 (CANL) - D8-16 (BAT) Ignition switch off 6 kΩ or higher
OK
REPLACE CAN JUNCTION CONNECTOR
NG
CONNECT CONNECTOR Click here
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CONNECT CONNECTOR
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Reconnect the D95 CAN junction connector.
NEXT
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CHECK FOR SHORT IN CAN BUS WIRE (HEADLIGHT ECU)
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Disconnect the headlight swivel ECU assembly*1 or headlight leveling ECU assembly*2 connector.
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*1: w/ Adaptive Front-lighting System
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*2: w/o Adaptive Front-lighting System
Text in Illustration *A w/ Adaptive Front-lighting System *B w/o Adaptive Front-lighting System *a Rear view of wire harness connector
(to Headlight Swivel ECU Assembly)
*b Front view of wire harness connector
(to Headlight Leveling ECU Assembly)
*c Front view of DLC3 - - -
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Measure the resistance according to the value(s) in the table below.
Standard Resistance w/ Adaptive Front-lighting System Tester Connection Switch Condition Specified Condition A38-12 (CANH) - A38-13 (CANL) Ignition switch off 54 to 69 Ω A38-12 (CANH) - D8-4 (CG) Ignition switch off 200 Ω or higher A38-13 (CANL) - D8-4 (CG) Ignition switch off 200 Ω or higher A38-12 (CANH) - D8-16 (BAT) Ignition switch off 6 kΩ or higher A38-13 (CANL) - D8-16 (BAT) Ignition switch off 6 kΩ or higher w/o Adaptive Front-lighting System Tester Connection Switch Condition Specified Condition A82-6 (CANH) - A82-7 (CANL) Ignition switch off 54 to 69 Ω A82-6 (CANH) - D8-4 (CG) Ignition switch off 200 Ω or higher A82-7 (CANL) - D8-4 (CG) Ignition switch off 200 Ω or higher A82-6 (CANH) - D8-16 (BAT) Ignition switch off 6 kΩ or higher A82-7 (CANL) - D8-16 (BAT) Ignition switch off 6 kΩ or higher Result Result Proceed to OK (w/ Adaptive Front-lighting System) A OK (for LHD, w/o Adaptive Front-lighting System) B OK (for RHD, w/o Adaptive Front-lighting System) C NG D
A
REPLACE HEADLIGHT SWIVEL ECU ASSEMBLY Click here
B
REPLACE HEADLIGHT LEVELING ECU ASSEMBLY Click here
C
REPLACE HEADLIGHT LEVELING ECU ASSEMBLY Click here
D
REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO HEADLIGHT ECU (CANH, CANL)
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CONNECT CONNECTOR
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Reconnect the D93 and D95 CAN junction connectors.
NEXT
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CHECK FOR SHORT IN CAN BUS WIRE (POWER MANAGEMENT CONTROL ECU)
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Text in Illustration *a Rear view of wire harness connector
(to Power Management Control ECU)
*b Front view of DLC3 Disconnect the power management control ECU connector.
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Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Switch Condition Specified Condition D111-26 (CA2H) - D111-25 (CA2L) Ignition switch off 108 to 132 Ω D111-26 (CA2H) - D8-4 (CG) Ignition switch off 200 Ω or higher D111-25 (CA2L) - D8-4 (CG) Ignition switch off 200 Ω or higher D111-26 (CA2H) - D8-16 (BAT) Ignition switch off 6 kΩ or higher D111-25 (CA2L) - D8-16 (BAT) Ignition switch off 6 kΩ or higher
OK
REPLACE POWER MANAGEMENT CONTROL ECU Click here
NG
REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO POWER MANAGEMENT CONTROL ECU (CA2H, CA2L)
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CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - BATTERY AND BODY GROUND)
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Text in Illustration *a Rear view of wire harness connector
(to Power Management Control ECU)
Connect the cable to the negative (-) battery terminal.
Note
When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.
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Disconnect the power management control ECU connector.
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Measure the voltage according to the value(s) in the table below.
Standard Voltage Tester Connection Condition Specified Condition D111-2 (AM21) - Body ground Always 11 to 14 V D111-1 (AM22) - Body ground Always 11 to 14 V -
Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Condition Specified Condition D111-6 (GND) - Body ground Always Below 1 Ω D111-5 (GND2) - Body ground Always Below 1 Ω
OK
REPLACE POWER MANAGEMENT CONTROL ECU Click here
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
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