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   6 

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   6 

A: Go to next step 

1. Disconnect the driving support ECU assembly connector.
   Fig 1: Checking L151 Connector Terminals

   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
   L151-25 (GND) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

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

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 for which radar cruise control operation is possible.
   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   7 

A → END