C1251

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: C1251: Open in Pump Motor Circuit
C1251 - Open in Pump Motor Circuit

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.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* When replacing the master cylinder solenoid, perform zero point calibration Calibration.
* Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT
Remove the hydraulic brake booster before the inspection Removal.

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (MOTOR RELAY)

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON.

(d) Turn the Techstream on.

(e) Start the engine.

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

ABS/VSC/TRAC





(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.

NG -- CHECK CONNECTION OF PUMP MOTOR WIRE HARNESS
OK -- Continue to next step.

2. RECONFIRM DTC

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

(b) Turn the ignition switch off.

(c) Check if the same DTC is output Reading and Clearing Diagnostic Trouble Codes.

Result





B -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

A -- REPLACE MASTER CYLINDER SOLENOID Disassembly

3. CHECK CONNECTION OF PUMP MOTOR WIRE HARNESS

(a) Remove the hydraulic brake booster assembly Removal.

(b) Check the tightening torque of the 2 screws which secure the wire harness connecting the master cylinder solenoid and brake booster with accumulator pump assembly.

OK:

The harness is tightened to the specified torque.

Torque : 2.9 Nm (30 kgf-cm, 26 in-lbf)

NG -- RETIGHTEN SCREWS
OK -- Continue to next step.

4. CHECK RESISTANCE OF PUMP MOTOR WIRE HARNESS

(a) Using a screwdriver, remove the 2 screws and pull out the wire harness from the master cylinder solenoid.





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

Standard Resistance:





Text in Illustration





NG -- REPLACE BRAKE BOOSTER WITH ACCUMULATOR PUMP ASSEMBLY Disassembly
OK -- Continue to next step.

5. RECONFIRM DTC

(a) Reassemble the hydraulic brake booster assembly Reassembly.

(b) Install the hydraulic brake booster assembly Installation.

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

(d) Turn the ignition switch off.

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

Result





B -- END

A -- REPLACE MASTER CYLINDER SOLENOID Disassembly