DTC U0122: Lost Communication with Vehicle Dynamics Control Module; DTC U0123: Lost Communication with Yaw Rate Sensor Module; DTC U0126: Lost Communication with Steering Angle Sensor Module; DTC U0140: Lost Communication With J/B ECU; DTC U0151: Lost Communication with Airbag ECU; DTC U0293: Lost Communication with HV ECU; DTC U1100: Lost Communication with Seat Belt Control ECU; DTC U1104: Lost Communication with Driving Support ECU: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / Pre-Collision and Pre-Collision 2 / Trouble Codes.
5. Check for DTCs.

   Result

   Result	Proceed to
   DTC U1104 is output	A
   DTC U1104 is not output	B

B → See step   8 

A: Go to next step 

1. Disconnect the L60 driving support ECU assembly connector.
2. Disconnect the A2 millimeter wave radar sensor connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A2-4 (LRRD) - L60-38 (LRRD)	Always	Below 1 Ω
   L60-38 (LRRD) - Body ground	Always	10 kΩ or higher
   L60-25 (GND) - Body ground	Always	Below 1 Ω
   A2-2 (SGND) - Body ground	Always	Below 1 Ω

4. Reconnect the L60 driving support ECU assembly connector.
5. Reconnect the A2 millimeter wave radar sensor connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVING SUPPORT ECU - MILLIMETER WAVE RADAR SENSOR) 

OK: Go to next step 

1. Select "CAN Bus Check" from the "System Selection" on the Techstream.
2. Select "Communication Malfunction DTC" from the "CAN Bus Check" screen, and then select "Enter".

   OK

   CAN communication is normal.

NG → See step   8 

OK: Go to next step 

1. Disconnect the A2 millimeter wave radar sensor connector.
2. Disconnect the L60 driving support ECU assembly connector.
   Fig 1: Checking Voltage Of Driving Support ECU Assembly (B Circuit)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   L60-30 (B) - Body ground	Power switch on (IG)	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

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

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (B CIRCUIT) 

OK: Go to next step 

1. Measure the voltage according to the value(s) in the table below.
   Fig 2: Measuring Voltage Of Millimeter Wave Radar Sensor (IGB Circuit) With A2 Connector End View

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A2-5 (IGB) - Body ground	Power switch on (IG)	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

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

2. Reconnect the A2 millimeter wave radar sensor connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (IGB CIRCUIT) 

OK: Go to next step 

1. Replace the millimeter wave radar sensor. Refer to REMOVAL .
2. Adjust the millimeter wave radar sensor. Refer to ADJUSTMENT .

NEXT: Go to next step 

1. Clear the DTCs. Refer to DTC CHECK / CLEAR .
2. Turn the cruise control main switch on.
3. Drive the vehicle at the required speed (45 km/h (28 mph) or higher).
4. Check if the same DTC is output. Refer to DTC CHECK / CLEAR .

   Result

   Result	Proceed to
   DTC U1104 is not output	A
   DTC U1104 is output	B

B → See step   9 

A → END (MILLIMETER WAVE RADAR SENSOR WAS DEFECTIVE)