Open in Pump Motor Circuit - Vehicle Stability Control System

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: 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
NOTE: When replacing the master cylinder solenoid, perform zero point calibration. Programming and Relearning
HINT: Remove the hydraulic brake booster assembly before the inspection.

PROCEDURE

1. CHECK CONNECTION OF PUMP MOTOR WIRE HARNESS
(a) Using a screwdriver, remove the 2 plugs from the hydraulic brake booster assembly.

(b) Check the tightening torque of the 2 screws which tighten the wire harness connecting the hydraulic brake booster assembly and brake booster pump.
OK:
The harness is tightened to the specific 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 the wire harness from the hydraulic brake booster assembly.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- REPLACE BRAKE BOOSTER PUMP ASSEMBLY
OK -- Continue to next step.
3. RECONFIRM DTC
(a) Reassemble the hydraulic brake booster assembly.
(b) Install the hydraulic brake booster assembly.
(c) Clear the DTC. Reading and Clearing Diagnostic Trouble Codes
(d) Check if the same DTC is output. Reading and Clearing Diagnostic Trouble Codes

Result





B -- USE SIMULATION METHOD TO CHECK
A -- REPLACE MASTER CYLINDER SOLENOID