Inspection Procedure

HINT:

When C1241/41 is output together with C0278/11 and/or C0279/12, inspect and repair the trouble areas indicated by C1241/41 first (See DTC C1241/41 LOW BATTERY POSITIVE VOLTAGE OR ABNORMALLY HIGH BATTERY POSITIVE VOLTAGE  ).

1. INSPECT ABS NO. 3 FUSE 
   1. Remove the ABS NO. 3 fuse from the engine room relay block.
   2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      RESISTANCE SPECIFIED CONDITIONS
      
      

      Tester Connection	Condition	Specified Condition
      ABS NO. 3 (30 A) fuse	Always	Below 1 Ω

      NG: REPLACE ABS NO. 3 FUSE 

      Fig 1: Identifying ABS No. 3 Fuse

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

2. INSPECT SKID CONTROL ECU (+BS TERMINAL) 
   1. Install the ABS NO. 3 fuse.
   2. Disconnect the skid control ECU connector.
   3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage 

      VOLTAGE SPECIFIED CONDITIONS
      
      

      Tester Connection	Condition	Specified Condition
      A38-12 (+BS) - Body ground	Always	11 to 14 V

      NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (+BS CIRCUIT) 

      Fig 2: Identifying Terminal +BS Of A38 Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

3. INSPECT SKID CONTROL ECU (GND1 TERMINAL) 
   1. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      RESISTANCE SPECIFIED CONDITIONS
      
      

      Tester Connection	Condition	Specified Condition
      A38-1 (GND1) - Body ground	Always	Below 1 Ω

      NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT) 

      Fig 3: Identifying Terminal GND1 Of A38 Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

4. RECONFIRM DTC 

   HINT:

   This code is detected when a problem is identified in the brake actuator assembly.

   The solenoid circuit is in the brake actuator assembly. Therefore, solenoid circuit inspection and solenoid unit inspection cannot be performed. Be sure to check if the DTC is output before replacing the brake actuator assembly.

   1. Reconnect the skid control ECU connector.
   2. Clear the DTCs (See DTC CHECK / CLEAR  ).
   3. Start the engine.
   4. Drive the vehicle at a speed of 20 km/h (12 mph) or more for 30 seconds or more.
   5. Check if the same DTC is recorded (See DTC CHECK / CLEAR  ).

      Result 

      DTC OUTPUT RESULT
      
      

      Result	Proceed to
      DTCs (C0278/11 and C0279/12) are not output	A
      DTCs (C0278/11 and/or C0279/12) are output	B

      HINT:

      • If a speed signal of 6 km/h (4 mph) or more is input to the skid control ECU with the ignition switch ON and the stop light switch off, the ECU performs self diagnosis of the motor and solenoid circuits.
      • If the normal system code is output (no trouble codes are output), slightly jiggle the connectors, wire harnesses, and fuses of the brake actuator assembly. Make sure that no DTCs are output.
      • If any DTCs are output while jiggling a connector or wire harness of the brake actuator assembly (skid control ECU), inspect and repair the connector or wire harness.
      • It is suspected that the DTCs were output due to a bad connection of the connector terminal.

        B: REPLACE BRAKE ACTUATOR ASSEMBLY  (See REMOVAL  )

        A: CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)  (See DIAGNOSIS SYSTEM  )