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 U0293: Lost Communication with HV 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 tester on.
4. Enter the following menus: Powertrain / Radar Cruise / Trouble Codes.
5. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.
6. Check for DTCs.

   Result

   Result	Proceed to
   DTC U1104 is output (for Radar Cruise)	A
   DTC U1104 is output (for Hybrid Control)	B
   DTCs other than U1104 are output	B

B → See step   7 

A: Go to next step 

1. Using the Techstream to check if the CAN communication system is functioning normally. Refer to HOW TO PROCEED WITH TROUBLESHOOTING .

   Result

   Result	Proceed to
   CAN communication is normal	A
   CAN communication is malfunctioning	B

B → See step   7 

A: Go to next step 

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

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   L60-38 (LRRD) - A2-4 (LRRD)	Always	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   L60-38 (LRRD) or A2-4 (LRRD) - Body ground	Always	10 kΩ or higher

3. Reconnect the driving support ECU assembly and millimeter wave radar sensor assembly connectors.

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

OK: Go to next step 

1. Disconnect the driving support ECU assembly connector.
   Fig 1: Checking Harness And Connector (Driving Support ECU Assembly - Body Ground) With L60 Connector End View

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   L60-25 (GND) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

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

3. Reconnect the driving support ECU assembly connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - BODY GROUND) 

OK: Go to next step 

1. Replace the driving support control ECU assembly. Refer to REMOVAL .

NEXT: Go to next step 

1. Connect the Techstream to DLC3.
2. Turn the power switch on (IG).
3. Clear the DTCs. Refer to DTC CHECK / CLEAR .
4. Perform the following to make sure that the DTC detection conditions are met.

   HINT: 

   If the detection conditions are not met, the malfunction cannot be detected.

   1. Drive the vehicle at a speed of between approximately 50 km/h (30 mph) and 170 km/h (105 mph).
   2. Turn the cruise control system on using the cruise control switch (ON-OFF button).
   3. Push the cruise control switch to -/SET to begin control of vehicle speed using the cruise control system.
5. Enter the following menus: Powertrain / Radar Cruise / Trouble Codes.
6. Check for DTCs.

   Result

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

B → See step   8 

A → END