Last Modified: 7-3-2017 6.8:8.0.40 Doc ID: RM000001A5M007X
Model Year Start: 2007 Model: LX470 Prod Date Range: [08/2006 -           ]
Title: BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: C0278/11,C0279/12; Open or Short Circuit in ABS Solenoid Relay Circuit; 2007 MY LX470 [08/2006 -        ]

DTC

C0278/11

Open or Short Circuit in ABS Solenoid Relay Circuit

DTC

C0279/12

Short to B+ in ABS Solenoid Relay Circuit

DESCRIPTION

This relay supplies power to each ABS solenoid. After the ignition switch is turned ON, if the initial check is OK, the relay turns on.

DTC No.

DTC Detection Condition

Trouble Area

C0278/11

Conditions 1. and 2. continue for 0.2 sec. or more:

  1. ECU terminal IG1 voltage is 9.5 V to 17.0 V and the solenoid relay is ON; however, the contact point of the solenoid relay is OFF.
  2. With solenoid relay ON, ECU terminal IG1 voltage becomes 9.5 V or less and the contact point of the solenoid relay does not become ON.
  • ABS solenoid relay
  • ABS solenoid relay circuit

C0279/12

Immediately after ECU terminal IG1 becomes ON, and solenoid relay is OFF; however, when the condition that the solenoid relay due to the contact point is ON continues for 0.2 sec. or more.

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

When using the intelligent tester, start from *1. When not using the intelligent tester, start from *2.

PROCEDURE

1.

PERFORM ACTIVE TEST (ABS SOLENOID RELAY)*1

(a) Select the ACTIVE TEST, generate a control command, and then check that the ABS solenoid relay operates.

Skid control ECU assembly

Item

Vehicle Condition / Test Details

Diagnostic Note

SOL RELAY

Turns ABS solenoid relay ON / OFF

Operation of solenoid (clicking sound) can be head

OK:

Operation sound of the ABS solenoid relay should be heard.

OK

GO TO STEP 6

NG

2.

CHECK WIRE HARNESS (BRAKE ACTUATOR - ENGINE ROOM RELAY BLOCK)*2

(a) Remove the ABS SOL relay from the engine room relay block.

(b) Disconnect the A43 actuator connector.

(c) Measure the resistance of the wire harness side connectors.

Standard resistance:

Tester Connection

Specified Condition

A43-4 (BS) - Relay block ABS SOL relay terminal 3

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

3.

INSPECT RELAY (Marking: ABS SOL)

(a) Remove the ABS SOL relay from the engine room relay block.

(b) Measure the resistance of the relay.

Standard resistance:

Tester Connection

Specified Condition

1 - 3

10 kΩor higher

1 - 3

Below 1 Ω

(when battery voltage is applied to terminal 4 and 6)
NG

REPLACE RELAY

OK

4.

INSPECT BRAKE ACTUATOR

(a) Disconnect the A43 and A44 actuator connectors.

(b) Measure the resistance of the actuator.

Standard resistance:

Tester Connection

Specified Condition

A43-4 (BS) - A44-1 (AST)

30 to 36 Ω
NG

REPLACE BRAKE ACTUATOR

OK

5.

CHECK WIRE HARNESS (SKID CONTROL ECU ASSEMBLY - ABS SOLENOID RELAY)
NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

CHECK EACH CONNECTION IF SAME CODE IS STILL OUTPUT AFTER DTC DELETION (IF CONNECTOR IS NORMAL, SKID CONTROL ECU MAY BE DEFECTIVE)

6.

CHECK WIRE HARNESS (SKID CONTROL ECU ASSEMBLY - BRAKE ACTUATOR)

(a) Check for open circuit in harness and connectors.

NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

7.

CHECK OPERATION OF BRAKE ACTUATOR WITH NEW OR NORMALLY FUNCTIONING BRAKE ACTUATOR

(a) Temporarily replace the brake actuator with a new or normally functioning one.

(b) Check that the malfunction disappears.

OK:

Malfunction disappears.

NG

REPLACE SKID CONTROL ECU ASSEMBLY

OK

REPLACE BRAKE ACTUATOR