DTC U0122: Lost Communication with Vehicle Stability Control Module; DTC U0129: Lost Communication with Brake System Control Module: Procedure

1. Reconfirm DTCs.

   HINT: 

   If DTC U1107-436 is output from Gateway of the power management control ECU, this indicates a sub bus 15 malfunction. Troubleshoot for DTC U1107-436 and check for malfunctions in sub bus 15.

   RESULT
   
   

   Result	Proceed to
   DTC U1107-436 is not output from power management control ECU.	A
   DTC U1107-436 is not output from power management control ECU.	B

B → See step   5 

A: Go to next step 

1. Disconnect the cable from the negative (-) auxiliary battery terminal.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Disconnect the skid control ECU assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A16-9 (CANH) - A16-8 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	54 to 69 Ω

   TEXT IN ILLUSTRATION
   
   

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

NG → REPAIR OR REPLACE SKID CONTROL ECU ASSEMBLY CAN BRANCH WIRE OR CONNECTOR (CANH, CANL) 

OK: Go to next step 

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NOTE:

   When connecting the cable, some systems need to be initialized after the cable is reconnected. Refer to INITIALIZATION [03/2012 - ] .

2. Disconnect the skid control ECU assembly connector.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A14-43 (+BI1) - Body ground	Always	11 to 14 V
   A14-29 (+BI3) - Body ground	Always	11 to 14 V
   A16-38 (+BI2) - Body ground	Always	11 to 14 V
   A16-22 (+BI4) - Body ground	Always	11 to 14 V
   A14-46 (IG1) - Body ground	Power switch on (IG)	11 to 14 V
   A16-46 (IG2) - Body ground	Power switch on (IG)	11 to 14 V

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A14-1 (GND) - Body ground	Always	Below 1 Ω
   A16-1 (GND4) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

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

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   4