Toyota Venza: Open or Short Circuit in ABS Solenoid Relay Circuit (C0278/11)

Toyota Venza Service Manual / Brake Control / Dynamic Control Systems / Vehicle Stability Control System / Open or Short Circuit in ABS Solenoid Relay Circuit (C0278/11)

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 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 brake actuator assembly.

DTC Code	DTC Detection Condition	Trouble Area
C0278/11	Either of the following is detected: 3 or more solenoid valves are determined to be fault and voltage supplied to the solenoid to be fault at the same time. Solenoid valve relay is not turned off.	Fusible link block (ABS NO. 2 fuse) ABS solenoid relay circuit Brake actuator assembly (ABS solenoid relay)

WIRING DIAGRAM

Refer to DTCs C0226/21, C0236/22, C0246/23, C0256/24, C1225/25, C1226/26, C1227/27 and C1228/28 (See page ).

CAUTION / NOTICE / HINT

HINT:

When C1241/41 is output together with C0278/11, inspect and repair the trouble areas indicated by C1241/41 first (See page ).

PROCEDURE

1.	INSPECT ABS NO. 2 FUSE

(a) Remove the fusible link block from the engine room relay block.

(b) Check if the fusible link is melted.

OK:

The fusible link is not melted.

Standard Resistance:

Tester Connection	Condition	Specified Condition
ABS NO. 2 (30 A) fuse - Body ground	Always	Below 1 Ω

Text in Illustration

*1	Engine Room Relay Block
*2	Fusible Link Block
*3	ABS NO. 2 Fuse

REPLACE FUSIBLE LINK BLOCK (ABS NO. 2 FUSE)

2.	INSPECT SKID CONTROL ECU (+BS TERMINAL)

(a) Install the fusible link block to the engine room relay block.

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

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A42-3 (+BS) - Body ground	Always	11 to 14 V

Text in Illustration

*1	Front view of wire harness connector (to Brake Actuator (Skid Control ECU))

REPAIR OR REPLACE HARNESS OR CONNECTOR (+BS CIRCUIT)

3.	INSPECT SKID CONTROL ECU (GND1 TERMINAL)

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A42-4 (GND1) - Body ground	Always	Below 1 Ω

Text in Illustration

*1	Front view of wire harness connector (to Brake Actuator (Skid Control ECU))

REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT)

4.	RECONFIRM DTC

HINT:

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

The solenoid circuit is located 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 (See page ).

(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 (See page ).

Result	Proceed to
DTC (C0278/11) is not output	A
DTC (C0278/11) is output	B

HINT:

If a speed signal of 15 km/h (9 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 (the trouble code is not 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.

CHECK FOR INTERMITTENT PROBLEMS

REPLACE BRAKE ACTUATOR ASSEMBLY

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