DTC U0122: Lost Communication with Vehicle Dynamics Control Module; DTC U0129: Lost Communication with Brake System Control Module [09/2015 - ]: Procedure

Result:  NEXT

NEXT 

See step  2

1. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the 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 [09/2015 - ] ).

Result:  NEXT

NEXT 

See step  3

1. Disconnect the skid control ECU assembly connectors.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Resistance

   STEERING BUS
   
   

   Tester Connection	Switch Condition	Specified Condition
   A21-30 (CA1H) - A21-29 (CA1L)	Engine switch off	54 to 69 Ω

   BRAKING AND DRIVING BUS
   
   

   Tester Connection	Switch Condition	Specified Condition
   A19-7 (CA2H) - A19-6 (CA2L)	Engine switch off	54 to 69 Ω

   TEXT IN ILLUSTRATION
   
   

   *A	Steering Bus
   *B	Braking and Driving Bus
   *a	Front view of wire harness connector (to Skid Control ECU Assembly)

Result:  NG

NG 

REPAIR OR REPLACE SKID CONTROL ECU ASSEMBLY CAN BRANCH WIRE OR CONNECTOR (CA1H, CA1L, CA2H, CA2L) 

Result:  OK

OK 

See step  4

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NOTE:

   When disconnecting the cable, some systems need to be initialized after the cable is reconnected (Refer to INITIALIZATION [09/2015 - ] ).

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A19-43 (+BI1) - Body ground	Always	11 to 14 V
   A21-38 (+BI2) - Body ground	Always	11 to 14 V
   A19-29 (+BI3) - Body ground	Always	11 to 14 V
   A21-22 (+BI4) - Body ground	Always	11 to 14 V
   A19-46 (IG1) - Body ground	Engine switch on (IG)	11 to 14 V
   A21-46 (IG2) - Body ground	Engine switch on (IG)	11 to 14 V

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A19-1 (GND) - Body ground	Always	Below 1 Ω
   A21-1 (GND4) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Skid Control ECU Assembly)

Result:  OK

OK 

REPLACE SKID CONTROL ECU ASSEMBLY 

(Refer to REMOVAL [09/2015 - ] )

Result:  NG

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR