C1251

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: 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.





INSPECTION PROCEDURE

NOTICE:
When replacing the master cylinder solenoid, perform calibration Programming and Relearning.

HINT
Remove the hydraulic brake booster assembly before the inspection On-Vehicle Inspection.

PROCEDURE

1. 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 Reassembly.

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.

2. 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.

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

Result





B -- REPLACE MASTER CYLINDER SOLENOID Disassembly

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