C1251

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.






INSPECTION PROCEDURE
NOTE: When replacing the master cylinder solenoid, perform zero point calibration Programming and Relearning.
HINT: Remove the hydraulic brake booster before the inspection Removal.

PROCEDURE

1. CHECK BRAKE PUMP MOTOR WIRE HARNESS CONNECTION (MT+ / MT-)
(a) Using a screwdriver, remove the 2 plugs from the hydraulic brake booster Disassembly.
(b) Check the tightening torque of 2 screws which fasten the wire harness connecting the hydraulic brake booster and brake booster pump Reassembly.
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-).
Standard resistance:
Below 2 Ohms
NG -- REPLACE BRAKE BOOSTER PUMP ASSEMBLY
OK -- Continue to next step.
3. RECONFIRM DTC
(a) Reassemble the hydraulic brake booster, then reinstall the hydraulic brake booster.
(b) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
(c) Check if the same DTC is detected Reading and Clearing Diagnostic Trouble Codes.
Result:






B -- END
A -- REPLACE MASTER CYLINDER SOLENOID