Dtc U1002 Lost Communication With Gateway Module (Sensor Bus)

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL

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

CHECK FOR OPEN IN CAN BUS MAIN WIRE (DRIVING SUPPORT ECU ASSEMBLY - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

CONNECT CONNECTOR

CHECK FOR OPEN IN CAN BUS MAIN WIRE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - DRIVING SUPPORT ECU ASSEMBLY)

CHECK FOR SHORT IN CAN BUS WIRES (DRIVING SUPPORT ECU ASSEMBLY - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

CONNECT CONNECTOR

CHECK FOR SHORT IN CAN BUS WIRES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - DRIVING SUPPORT ECU ASSEMBLY)

CHECK HARNESS AND CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - BATTERY AND BODY GROUND)

DESCRIPTION

1. The driving support ECU assembly stores this DTC when no signals can be received from the ECUs that have been memorized as those connected to the parking assist bus.
   
2. When the driving support ECU assembly receives a response signal from the ECUs connected to the parking assist bus, the driving support ECU assembly recognizes and memorizes that the ECU is connected to the parking assist bus. Based on this memorized data, the driving support ECU assembly monitors for malfunctions in the ECUs connected to the parking assist bus when communicating with those ECUs. If the driving support ECU assembly cannot receive response signals from the ECUs that have been memorized as those connected to the parking assist bus, the driving support ECU assembly determines that a malfunction exists.
   
3. 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).
   

1. For vehicles with a pre-crash safety system.
   

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

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

1. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and CAN branch wire.
   

   CAUTION:

   Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the airbag system.

   NOTICE:

   1. After turning the engine 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 (LandCruiser RM000003YMD00TX.html).
      
   2. When disconnecting the cable, some systems need to be initialized after the cable is reconnected (LandCruiser RM000003YMF011X.html).
      

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

   Standard Resistance:

   Tester Connection	Switch Condition	Specified Condition	resistance: Malfunction
   G119-40 (CA1P) - G119-18 (CA1N)	Engine switch off	54 to 69 Ω	Below 53 Ω: Short in line
   G119-40 (CA1P) - G119-18 (CA1N)	Engine switch off	54 to 69 Ω	Higher than 70 Ω: Open in CAN main bus line
   G119-40 (CA1P) - G48-16 (BAT)	Engine switch off	6 kΩ or higher	Below 6 kΩ: +B short
   G119-18 (CA1N) - G48-16 (BAT)	Engine switch off	6 kΩ or higher	Below 6 kΩ: +B short
   G119-40 (CA1P) - G48-4 (CG)	Engine switch off	200 Ω or higher	Below 200 Ω: Ground short
   G119-18 (CA1N) - G48-4 (CG)	Engine switch off	200 Ω or higher	Below 200 Ω: Ground short

   Text in Illustration

   *a	Component with harness connected (Driving Support ECU Assembly)
   *b	Front view of DLC3

   Result

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

1. Disconnect the G119 driving support ECU assembly connector.
   

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

   Standard Resistance:

   Tester Connection	Switch Condition	Specified Condition
   G119-40 (CA1P) - G119-18 (CA1N)	Engine switch off	108 to 132 Ω

   Text in Illustration

   *a	Rear view of wire harness connector (to Driving Support ECU Assembly)

1. Reconnect the G119 driving support ECU assembly connector.
   

1. Disconnect the A15 millimeter wave radar sensor assembly connector.
   

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

   Standard Resistance:

   Tester Connection	Switch Condition	Specified Condition
   A15-4 (CA1P) - A15-3 (CA1N)	Engine switch off	108 to 132 Ω

   Text in Illustration

   *a	Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly)

1. Disconnect the G119 driving support ECU assembly connector.
   

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

   Standard Resistance:

   Tester Connection	Switch Condition	Specified Condition
   G119-40 (CA1P) - G119-18 (CA1N)	Engine switch off	108 to 132 Ω
   G119-40 (CA1P) - G48-4 (CG)	Engine switch off	200 Ω or higher
   G119-18 (CA1N) - G48-4 (CG)	Engine switch off	200 Ω or higher
   G119-40 (CA1P) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
   G119-18 (CA1N) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

   Text in Illustration

   *a	Rear view of wire harness connector (to Driving Support ECU Assembly)
   *b	Front view of DLC3

1. Reconnect the G119 driving support ECU assembly connector.
   

1. Disconnect the A15 millimeter wave radar sensor assembly connector.
   

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

   Standard Resistance:

   Tester Connection	Switch Condition	Specified Condition
   A15-4 (CA1P) - A15-3 (CA1N)	Engine switch off	108 to 132 Ω
   A15-4 (CA1P) - G48-4 (CG)	Engine switch off	200 Ω or higher
   A15-3 (CA1N) - G48-4 (CG)	Engine switch off	200 Ω or higher
   A15-4 (CA1P) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
   A15-3 (CA1N) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

   Text in Illustration

   *a	Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly)
   *b	Front view of DLC3

1. Connect the cable to the negative (-) battery terminal.
   

   NOTICE:

   When disconnecting the cable, some systems need to be initialized after the cable is reconnected (LandCruiser RM000003YMF011X.html).

2. Disconnect the G119 driving support ECU assembly connector.
   

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

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   G119-25 (GND) - Body ground	Always	Below 1 Ω

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

   Standard Voltage:

   Tester Connection	Switch Condition	Specified Condition
   G119-30 (B) - Body ground	Engine switch on (IG)	11 to 14 V