Toyota 4Runner: Pump Motor Relay (C1253)

Toyota 4Runner Service Manual / Brake / Brake Control / Dynamic Control Systems / Vehicle Stability Control System(for Hydraulic Brake Booster) / Pump Motor Relay (C1253)

DESCRIPTION

The motor relay (semiconductor relay) is built into the master cylinder solenoid and drives the pump motor based on a signal from the skid control ECU.

DTC Code	DTC Detection Condition	Trouble Area
C1253	There is a motor system circuit (motor input circuit) malfunction.	ABS NO. 1 fuse Motor relay circuit Master cylinder solenoid (Skid control ECU)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When replacing the master cylinder solenoid, perform calibration (See page ).

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1.	PERFORM ACTIVE TEST USING TECHSTREAM (MOTOR RELAY)

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Start the engine.

(f) Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test.

ABS/VSC/TRAC

Tester Display	Test Part	Control Range	Diagnostic Note
Motor Relay	Motor relay	Relay ON/OFF	An operating sound of the motor can be heard.

(g) Check the operating sound of the motor individually when operating it with the Techstream.

OK:

An operating sound of the motor can be heard.

GO TO STEP 3

2.	RECONFIRM DTC

(a) Clear the DTCs (See page ).

(b) Turn the ignition switch off.

(d) Turn the ignition switch to ON.

(e) Wait until the pump motor stops.

(f) Depress the brake pedal several times until the pump motor turns on. (Procedure A)

(g) Wait until the pump stops. (Procedure B)

(h) Repeat the above steps (procedure A and B) 3 more times.

(i) Check if the same DTC is output (See page
).

HINT:

Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

Result

Result	Proceed to
DTC is output	A
DTC is not output	B

REPLACE MASTER CYLINDER SOLENOID

USE SIMULATION METHOD TO CHECK

3.	CHECK TERMINAL VOLTAGE (+BM1, +BM2)

(a) Disconnect the A6 and A7 skid control ECU connectors.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A6-2 (+BM1) - Body ground	Always	11 to 14 V
A7-2 (+BM2) - Body ground	Always	11 to 14 V

Text in Illustration

*a	Front view of wire harness connector (to Skid Control ECU)

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.	CHECK HARNESS AND CONNECTOR (GND1, GND2 AND GND3 TERMINAL)

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	RECONFIRM DTC

(a) Clear the DTCs (See page ).

(b) Turn the ignition switch off.

(d) Turn the ignition switch to ON.

(e) Wait until the pump motor stops.

(f) Depress the brake pedal several times until the pump motor turns on. (Procedure A)

(g) Wait until the pump stops. (Procedure B)

(h) Repeat the above steps (procedure A and B) 3 more times.

(i) Check if the same DTC is output (See page
).

HINT:

Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

Result

Result	Proceed to
DTC is output	A
DTC is not output	B

REPLACE MASTER CYLINDER SOLENOID

USE SIMULATION METHOD TO CHECK

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