DTC U023A: Lost Communication with Front Camera Module [11/2017 - 01/2023]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the engine switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: System Select / Can Bus Check.

   Refer to DIAGNOSIS SYSTEM [11/2017 - 03/2019] , or refer to DIAGNOSIS SYSTEM [03/2019 - 09/2020] , or refer to DIAGNOSIS SYSTEM [09/2020 - 01/2023]

   CAN Bus Check 

   Result

   Result	Proceed to
   All of the ECUs and sensors that are currently connected to the CAN communication system are displayed	A
   None of the ECUs and sensors that are currently connected to the CAN communication system are displayed, or some of them are not displayed	B

Result: 

B 

GO TO CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2017 - 03/2019]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [03/2019 - 01/2023] 

Result: 

A 

See step  2

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [11/2017 - 01/2023]

   Body Electrical > Pre-Collision 2 > Clear DTCs 

2. Perform the following procedure.

   HINT: 

   If the following procedure is not performed, the previously output DTC cannot be detected.

   1. Turn the engine switch on (IG) and wait 2 seconds or more.
3. Check for DTCs.

   Refer to DTC CHECK / CLEAR [11/2017 - 01/2023]

   Body Electrical > Pre-Collision 2 > Trouble Codes 

   Result

   Result	Proceed to
   DTC U1002 is not output	A
   DTC U1002 is output	B

Result: 

B 

GO TO DTC CHART (U1002). Refer to  DTC U1002: Lost Communication with Gateway Module [11/2017 - 03/2019]  , or refer to  DTC U1002: Lost Communication with Gateway Module [03/2019 - 01/2023]  

Result: 

A 

See step  3

1. Disconnect the cable from the negative (-) battery terminal.
2. Disconnect the W18 forward recognition camera connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Forward Recognition Camera)

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   W18-6 (CANH) - W18-12 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

4. Connect the W18 forward recognition camera connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - FORWARD RECOGNITION CAMERA) 

Result: 

OK 

See step  4

1. Disconnect the W18 forward recognition camera connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Forward Recognition Camera)

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   W18-10 (GND) - Body ground	Always	Below 1 Ω

3. Connect the cable to the negative (-) battery terminal.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   W18-7 (IGB) - Body ground	Engine switch on (IG)	11 to 14 V

5. Connect the W18 forward recognition camera connector.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE FORWARD RECOGNITION CAMERA. Refer to  COMPONENTS [11/2017 - 01/2023] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)