Vehicle Stability Control System

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: C1251/51: Open in Pump Motor Circuit

DTC C1251/51 - 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

HINT: Remove the hydraulic brake booster before the inspection.

PROCEDURE

1. CHECK BRAKE PUMP MOTOR WIRE HARNESS CONNECTION (MT+ / MT-)
(a) Using a screwdriver, remove the 2 plugs from the hydraulic brake booster (Service and Repair).
(b) Check the tightening torque of 2 screws which fasten the wire harness connecting hydraulic brake booster and brake booster pump (Service and Repair).
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 (MT+/MT-)





(a) Using a screwdriver, remove the 2 screws and pull the wire harness from the hydraulic brake booster.
(b) Measure the resistance between the red wire (MT+) and black wire (MT-).
Resistance:
2 Ohms
NG -- REPLACE HYDRAULIC BRAKE BOOSTER
OK -- Continue to next step.
3. RECONFIRM DTC
(a) Reassemble the hydraulic brake booster, then reinstall the hydraulic brake booster.
(b) Clear the DTCs (Reading and Clearing Diagnostic Trouble Codes).
(c) Check if the same DTCs are detected.





B -- END
A -- REPLACE MASTER CYLINDER SOLENOID