Dtc C0278 Open In Abs Solenoid Relay Circuit

Brake. Corolla. Zre142 Aze141
Brake Control Dynamic Control Systems. Corolla. Zre142 Aze141

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT ABS NO. 3 FUSE

INSPECT SKID CONTROL ECU (+BS TERMINAL)

INSPECT SKID CONTROL ECU (GND1 TERMINAL)

RECONFIRM DTC

DTC C0278 Open in ABS Solenoid Relay Circuit

DTC C0279 Short in ABS Solenoid Relay Circuit


DESCRIPTION

The ABS solenoid relay supplies power to the ABS solenoid and TR(A)C solenoid.
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 self diagnosis performed when the vehicle starts running.
The ABS solenoid relay is housed in the skid control ECU in the actuator assembly.

DTC Code
DTC Detection Condition
Trouble Area
C0278
Either of the following is detected:
  1. Both of the following conditions continue for 0.2 seconds or more.
    1. The IG1 terminal voltage is 9.5 V or more.
    2. The solenoid relay contact is open when the relay is ON.
  2. Both of the following conditions continue for 0.2 seconds or more.
    1. The IG1 terminal voltage becomes lower than 9.5 V when the relay is turned on.
    2. The relay contact remains open.
  1. ABS NO. 3 fuse
  2. ABS solenoid relay circuit
  3. Brake actuator assembly (ABS 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. ABS solenoid relay circuit
  2. Brake actuator assembly (ABS solenoid relay)

WIRING DIAGRAM

Refer to DTCs C0226, C0236, C0246, C0256 and C1225 (Link).

INSPECTION PROCEDURE

NOTICE:
When replacing the brake actuator assembly, perform zero point calibration (COROLLA_ZRE142 RM000000XHR08KX.html).
HINT:
When C1241 and/or C1417 is output together with C0278 and/or C0279, inspect and repair the trouble areas indicated by C1241 and/or C1417 first (COROLLA_ZRE142 RM000000XW60EIX.html, or COROLLA_ZRE142 RM00000368W05LX.html).
1.INSPECT ABS NO. 3 FUSE


    Corolla. Zre142 Aze141.Brake Control Dynamic Control Systems.Anti-Lock Brake System. Dtc C0278 Open In Abs Solenoid Relay Circuit

  1. Remove the ABS NO. 3 fuse from the engine room relay block.

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

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


NG
REPLACE ABS NO. 3 FUSE
OK


2.INSPECT SKID CONTROL ECU (+BS TERMINAL)


    Corolla. Zre142 Aze141.Brake Control Dynamic Control Systems.Anti-Lock Brake System. Dtc C0278 Open In Abs Solenoid Relay Circuit

  1. Install the ABS NO. 3 fuse.

  1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

  1. Disconnect the skid control ECU connector.

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    A66-12 (+BS) - Body ground
    		Always
    		11 to 14 V


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


3.INSPECT SKID CONTROL ECU (GND1 TERMINAL)


    Corolla. Zre142 Aze141.Brake Control Dynamic Control Systems.Anti-Lock Brake System. Dtc C0278 Open In Abs Solenoid Relay Circuit

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A66-1 (GND1) - Body ground
    		Always
    		Below 1 Ω


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


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.

  1. Clear the DTCs (COROLLA_ZRE142 RM000000XHV0F2X.html).

  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 recorded (COROLLA_ZRE142 RM000000XHV0F2X.html).

    Result:

    Result
    		Proceed to
    DTCs (C0278 and C0279) are not output
    		A
    DTCs (C0278 and/or C0279) are output
    		B
    HINT:
    1. 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.
    2. 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.
    3. 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.
    4. It is suspected that the DTCs were output due to a bad connection of the connector terminal.


B
REPLACE BRAKE ACTUATOR ASSEMBLY (COROLLA_ZRE142 RM000003CZU00MX.html)
A

CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) (COROLLA_ZRE142 RM000000XHP0EKX.html)