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

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.
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.
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).	V2 bus circuit Power management control ECU CAN main wire or connector Headlight swivel ECU assembly (AFS ECU) CAN branch wire or connector* Power management control ECU Headlight swivel ECU assembly (AFS ECU)* CAN junction connector
U0073	Control module communication bus is off.	V2 bus circuit Power management control ECU CAN main wire or connector Headlight swivel ECU assembly (AFS ECU) CAN branch wire or connector* Power management control ECU Headlight swivel ECU assembly (AFS ECU)* CAN junction connector

*: w/ Adaptive Front-lighting System
For vehicles with an entry and start system.

WIRING DIAGRAM

INSPECTION PROCEDURE

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

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
DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL
1. 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

CHECK CAN BUS WIRE (CHECK MAIN WIRE FOR DISCONNECTION, CHECK BUS LINE FOR SHORT CIRCUIT)

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
D109-26 (CA2H) - D109-25 (CA2L)	Ignition switch off	54 to 69 Ω	Below 54 Ω: Short in line
D109-26 (CA2H) - D109-25 (CA2L)	Ignition switch off	54 to 69 Ω	Higher than 69 Ω: Open in CAN main bus line
D109-26 (CA2H) - D109-2 (AM21)	Ignition switch off	6 kΩ or higher	Below 6 kΩ: +B short
D109-25 (CA2L) - D109-2 (AM21)	Ignition switch off	6 kΩ or higher	Below 6 kΩ: +B short
D109-26 (CA2H) - D109-6 (GND)	Ignition switch off	200 Ω or higher	Below 200 Ω: Ground short
D109-25 (CA2L) - D109-6 (GND)	Ignition switch off	200 Ω or higher	Below 200 Ω: Ground short

Result
Result	Proceed to
NG Open in CAN main bus line	A
NG Short in line +B short GND short	B
OK	C

CHECK FOR SHORT IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - HEADLIGHT SWIVEL ECU ASSEMBLY) Click here

CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - BATTERY AND BODY GROUND) Click here

CHECK FOR OPEN IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - POWER MANAGEMENT CONTROL ECU)

Text in Illustration

*a
Rear view of wire harness connector

(to CAN Junction Connector)

Disconnect the D93 CAN junction connector.

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

CONNECT CONNECTOR Click here

REPLACE CAN JUNCTION CONNECTOR

CONNECT CONNECTOR
1. Reconnect the D93 CAN junction connector.
NEXT

CHECK FOR OPEN IN CAN BUS WIRE (POWER MANAGEMENT CONTROL ECU - CAN JUNCTION CONNECTOR)

Text in Illustration

*a
Rear view of wire harness connector

(to Power Management Control ECU)

Disconnect the D109 power management control ECU connector.

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

Standard Resistance

Tester Connection	Switch Condition	Specified Condition
D109-26 (CA2H) - D109-25 (CA2L)	Ignition switch off	108 to 132 Ω

REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO POWER MANAGEMENT CONTROL ECU (POWER MANAGEMENT CONTROL ECU - CAN JUNCTION CONNECTOR)

REPLACE POWER MANAGEMENT CONTROL ECU Click here

CHECK FOR SHORT IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - HEADLIGHT SWIVEL ECU ASSEMBLY)

Note

For vehicles without an adaptive front-lighting system, go to "Check for Short in CAN Bus Wire (CAN Junction Connector - Power Management Control ECU)".

Text in Illustration
*a	Rear view of wire harness connector (to CAN Junction Connector)
*b	Front view of DLC3

Disconnect the D95 CAN junction connector.

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

CONNECT CONNECTOR Click here

CHECK FOR SHORT IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - POWER MANAGEMENT CONTROL ECU)

Text in Illustration
*a	Rear view of wire harness connector (to CAN Junction Connector)
*b	Front view of DLC3

Disconnect the D93 CAN junction connector.

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

CONNECT CONNECTOR Click here

REPLACE CAN JUNCTION CONNECTOR

CONNECT CONNECTOR
1. Reconnect the D95 CAN junction connector.
NEXT

CHECK FOR SHORT IN CAN BUS WIRE (HEADLIGHT SWIVEL ECU ASSEMBLY)

Text in Illustration
*a	Rear view of wire harness connector (to Headlight Swivel ECU Assembly [AFS ECU])
*b	Front view of DLC3

Disconnect the A38 headlight swivel ECU assembly (AFS ECU) connector.

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

Standard Resistance

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

REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO HEADLIGHT SWIVEL ECU ASSEMBLY (CANH, CANL)

REPLACE HEADLIGHT SWIVEL ECU ASSEMBLY (AFS ECU) Click here

CONNECT CONNECTOR
1. Reconnect the D93 and D95 CAN junction connectors.
NEXT

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

Text in Illustration
*a	Rear view of wire harness connector (to Power Management Control ECU)
*b	Front view of DLC3

Disconnect the D109 power management control ECU connector.

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

Standard Resistance

Tester Connection	Switch Condition	Specified Condition
D109-26 (CA2H) - D109-25 (CA2L)	Ignition switch off	108 to 132 Ω
D109-26 (CA2H) - D8-4 (CG)	Ignition switch off	200 Ω or higher
D109-25 (CA2L) - D8-4 (CG)	Ignition switch off	200 Ω or higher
D109-26 (CA2H) - D8-16 (BAT)	Ignition switch off	6 kΩ or higher
D109-25 (CA2L) - D8-16 (BAT)	Ignition switch off	6 kΩ or higher

REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO POWER MANAGEMENT CONTROL ECU (CA2H, CA2L)

REPLACE POWER MANAGEMENT CONTROL ECU Click here

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

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.
Disconnect the D109 power management control ECU connector.

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

Standard Voltage

Tester Connection	Condition	Specified Condition
D109-2 (AM21) - Body ground	Always	11 to 14 V
D109-1 (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
D109-6 (GND) - Body ground	Always	Below 1 Ω
D109-5 (GND2) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE POWER MANAGEMENT CONTROL ECU Click here