C0279

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: C0278, C0279: Open in ABS Solenoid Relay Circuit


DESCRIPTION

The ABS solenoid relay supplies power to the ABS solenoid and TRAC solenoid.

The solenoid relay is turned on 1.5 seconds after the engine switch is turned on (IG), 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.





WIRING DIAGRAM

Refer to DTCs C0226, C0236, C0246, C0256 and C1225 C0226.

INSPECTION PROCEDURE

NOTICE:
When replacing the brake actuator assembly, perform zero point calibration and store system information Calibration.

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 C1241, or C1417).

PROCEDURE

1. INSPECT ABS2 FUSE

(a) Remove the ABS2 fuse from the engine room No. 1 relay block.





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

Standard Resistance:





NG -- REPLACE ABS2 FUSE
OK -- Continue to next step.

2. INSPECT SKID CONTROL ECU (+BS TERMINAL)

(a) Install the ABS2 fuse.





(b) Make sure that there is no looseness at the locking part and the connecting part of the connectors.

(c) Disconnect the skid control ECU connector.

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

Standard Voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (+BS CIRCUIT)
OK -- Continue to next step.

3. INSPECT SKID CONTROL ECU (GND1 TERMINAL)

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





Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT)
OK -- Continue 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.

(a) Reconnect the skid control ECU connector.

(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(c) Start the engine.

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

(e) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.

Result:





HINT
- If a speed signal of 6 km/h (4 mph) or more is input to the skid control ECU with the engine switch on (IG) 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 Removal

A -- CHECK FOR INTERMITTENT PROBLEMS Electronic Circuit Inspection Procedure