DTC U0122: Lost Communication with Vehicle Stability Control Module; DTC U0129: Lost Communication with Brake System Control Module [09/2014 - 10/2015]: Procedure

1. Reconfirm DTCs.

   HINT: 

   If DTC U1002 is output from Gateway of the network gateway ECU, this indicates a sub bus 19 malfunction. Troubleshoot for DTC U1002 and check for malfunctions in sub bus 19.

   RESULT
   
   

   Result	Proceed to
   DTC U1002 is not output from network gateway ECU.	A
   DTC U1002 is output from network gateway ECU.	B

Result: 

B 

GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC 

(Refer to DTC U1002: Lost Communication with Gateway Module [09/2014 - 10/2015] )

Result: 

A 

See step  2

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A13-15 (CA2H) - A13-3 (CA2L)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Brake Actuator Assembly [Skid Control ECU])

Result: 

NG 

REPAIR OR REPLACE SKID CONTROL ECU BRANCH WIRE OR CONNECTOR (CA2H, CA2L) 

Result: 

OK 

See step  3

1. Connect the cable to the negative (-) 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 [09/2014 - 10/2015] ).

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A13-12 (+BS) - Body ground	Always	11 to 14 V
   A13-24 (BM) - Body ground	Always	11 to 14 V
   A13-34 (IG1) - 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
   A13-1 (GND1) - Body ground	Always	Below 1 Ω
   A13-13 (GND2) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Brake Actuator Assembly [Skid Control ECU])

Result: 

OK 

REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU) 

(Refer to REMOVAL [09/2014 - 10/2015] )

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR