Dtc C0278 Open In Abs Solenoid Relay Circuit


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK TERMINAL VOLTAGE (+BS TERMINAL)

CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)

RECONFIRM DTC

DTC C0278 Open in ABS Solenoid Relay Circuit

DTC C0279 Short in ABS Solenoid Relay Circuit


DESCRIPTION

The solenoid relay supplies power to the solenoids.
The solenoid relay is turned on 1.5 seconds after the ignition switch is turned to ON, and is turned off if an open or short in the solenoid is detected by the self-diagnosis performed when the engine starts running.
The solenoid relay is housed in the skid control ECU in the brake actuator assembly.

DTC Code
DTC Detection Condition
Trouble Area
C0278
Either condition is met:
  1. Both of the following conditions continue for 0.22 seconds or more.
    1. The IG1 terminal voltage is 9.5 V or higher.
    2. The relay contact is open when the relay is on.
  2. Both conditions are met for 0.22 seconds or more.
    1. The IG1 terminal voltage drops below 9.5V when the relay is turned on and remains below 9.5 V.
    2. The relay contact remains open.
  1. ABS NO. 2 fuse
  2. Solenoid relay circuit
  3. Brake actuator assembly (Solenoid relay)
C0279
Immediately after the ignition switch is turned to ON, the solenoid relay contact is closed for 4 seconds when the relay is turned off.
  1. Solenoid relay circuit
  2. Brake actuator assembly (Solenoid relay)

WIRING DIAGRAM

Refer to DTCs C0226, C0236, C0246, C0256 and C1225 (Toyota Fortuner RM000000XI80BGX.html).

INSPECTION PROCEDURE

NOTICE:
  1. After replacing the brake actuator assembly, perform calibration (Toyota Fortuner RM000000XHR06WX.html).
  2. Inspect the fuses for circuits related to this system before performing the following inspection procedure.
  3. Before disconnecting the connector, make sure that there are no problems with the connection.
  4. After disconnecting the connector, make sure that the connector case and terminals are not deformed or corroded.
HINT:
When DTC C1241 and/or C1417 is output together with DTC C0278 and/or C0279, inspect and repair the trouble areas indicated by DTC C1241 and/or C1417 first (Toyota Fortuner RM000000XW60C1X.html and/or Toyota Fortuner RM00000368W03NX.html).
1.CHECK TERMINAL VOLTAGE (+BS TERMINAL)

  1. Turn the ignition switch off.

  1. Disconnect the skid control ECU (brake actuator assembly) connector.



    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Brake Control.Vehicle Stability Control System. Dtc C0278 Open In Abs Solenoid Relay Circuit

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    S25-12 (+BS) - Body ground
    		Always
    		11 to 14 V
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to Skid Control ECU [Brake Actuator Assembly])


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


2.CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)

  1. Turn the ignition switch off.

  1. Disconnect the skid control ECU (brake actuator assembly) connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    S25-1 (GND1) - Body ground
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.RECONFIRM DTC
HINT:
These codes are stored when a problem is identified in the skid control ECU (brake actuator assembly). The solenoid circuit is in the skid control ECU (brake actuator assembly). Therefore, solenoid circuit inspections and solenoid unit inspections cannot be performed. Be sure to check if any DTCs are output before replacing the brake actuator assembly.

  1. Clear the DTC (Toyota Fortuner RM000000XHV0C7X.html).

  1. Turn the ignition switch off.

  1. Start the engine.

  1. Drive the vehicle at a speed of 20 km/h (12 mph) or more for 30 seconds or more.

  1. Check if the same DTC is output (Toyota Fortuner RM000000XHV0C7X.html).

    Result
    Result
    		Proceed to
    DTC is not output
    		A
    DTC is output
    		B
    HINT:
    1. If a speed signal of 6 km/h (4 mph) or more is input to the skid control ECU (brake actuator assembly) with the ignition switch ON and the stop light switch off, the ECU performs self-diagnosis of the motor and solenoid circuits.
    2. If the normal system code is output (the trouble code is not output), slightly jiggle the connectors, wire harnesses and fuses of the skid control ECU (brake actuator assembly). Make sure that no DTCs are output.
    3. If any DTCs are output while jiggling a connector or wire harness of the skid control ECU (brake actuator assembly), inspect and repair the connector or wire harness. The DTCs were probably stored due to a bad connection of the connector terminal.


B
REPLACE BRAKE ACTUATOR ASSEMBLY (Toyota Fortuner RM0000010K0010X.html)
A

USE SIMULATION METHOD TO CHECK (Toyota Fortuner RM0000012Q9013X.html)