DTC U0293: Lost Communication with HV ECU: Procedure

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

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

   NOTE:

   When disconnecting the cable, some systems need to be initialized after the cable is reconnected, refer to INITIALIZATION .

NEXT: Go to next step 

1. Disconnect the D73 hybrid vehicle control ECU connector.
   Fig 1: Disconnecting D73 Hybrid Vehicle Control ECU Connector

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

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition
   D73-31 (CA3P) - D73-30 (CA3N)	Ignition switch off	108 to 132 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Rear view of wire harness connector (to Hybrid Vehicle Control ECU)

NG → REPAIR OR REPLACE HYBRID VEHICLE CONTROL ECU CAN MAIN WIRE OR CONNECTOR (CA3P, CA3N) 

OK: Go to next step 

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

   When disconnecting the cable, some systems need to be initialized after the cable is reconnected, refer to INITIALIZATION .

   Fig 2: Disconnecting A65, A66 D72 And D73 Hybrid Vehicle Control ECU Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   TEXT IN ILLUSTRATION
   
   

   *a

   Rear view of wire harness connector (to Hybrid Vehicle Control ECU)

   -

   -

2. Disconnect the A65, A66 and D72 hybrid vehicle control ECU connectors.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   D72-6 (E1) - Body ground	Always	Below 1 Ω
   D72-5 (E01) - Body ground	Always	Below 1 Ω
   D73-4 (E12) - Body ground	Always	Below 1 Ω
   D73-5 (E02) - Body ground	Always	Below 1 Ω

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   D72-1 (BATT) - Body ground	Always	11 to 14 V
   A66-1 (IGSW) - Body ground	Ignition switch ON	11 to 14 V
   A66-5 (+B1) - Body ground	Battery positive (+) voltage applied to terminal A66-6 (MREL)	11 to 14 V
   A65-2 (+B2) - Body ground	Battery positive (+) voltage applied to terminal A66-6 (MREL)	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   4