Dtc C1251 Open In Pump Motor Circuit


DESCRIPTION

INSPECTION PROCEDURE

CHECK CONNECTION OF PUMP MOTOR WIRE HARNESS

CHECK RESISTANCE OF PUMP MOTOR WIRE HARNESS

RECONFIRM DTC

DTC 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.

DTC Code
DTC Detection Condition
Trouble Area
C1251
There is an open in the motor system circuit (motor input circuit).
  1. Pump motor wire harness connection
  2. Brake booster with accumulator pump assembly
  3. Master cylinder solenoid (Skid control ECU)

INSPECTION PROCEDURE

NOTICE:
When replacing the master cylinder solenoid, perform calibration (LandCruiser RM00000452J00ZX.html).
HINT:
Remove the hydraulic brake booster assembly before the inspection (for LHD: LandCruiser RM00000171W034X.html, for RHD: LandCruiser RM00000171W035X.html).
1.CHECK CONNECTION OF PUMP MOTOR WIRE HARNESS

  1. Remove the hydraulic brake booster assembly (for LHD: LandCruiser RM00000171T033X.html, for RHD: LandCruiser RM00000171T034X.html).

  1. 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 (for LHD: LandCruiser RM00000171V02GX.html, for RHD: LandCruiser RM00000171V02HX.html).

OK:
The harness is tightened to the specified torque.
Torque:
2.9 N*m{30 kgf*cm, 26 in.*lbf}


NG
RETIGHTEN SCREWS
OK


2.CHECK RESISTANCE OF PUMP MOTOR WIRE HARNESS

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



    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Brake Control Dynamic Control Systems.Anti-Lock Brake System. Dtc C1251 Open In Pump Motor Circuit

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    Red wire terminal - Black wire terminal
    		Always
    		Below 2 Ω
    Text in Illustration
    *1
    		Pump motor wire harness
    *a
    		Red wire
    *b
    		Black wire
HINT:
Refer to the brake booster with accumulator pump assembly installation procedures:
for LHD (LandCruiser RM00000171U02DX.html)
for RHD (LandCruiser RM00000171U02EX.html)


NG
REPLACE BRAKE BOOSTER WITH ACCUMULATOR PUMP ASSEMBLY
OK


3.RECONFIRM DTC

  1. Reassemble the hydraulic brake booster assembly (for LHD: LandCruiser RM00000171V02GX.html, for RHD: LandCruiser RM00000171V02HX.html).

  1. Install the hydraulic brake booster assembly (for LHD: LandCruiser RM00000171Q033X.html, for RHD: LandCruiser RM00000171Q034X.html).

  1. Clear the DTCs (LandCruiser RM0000046KV016X.html).

  1. Check if the same DTC is output (LandCruiser RM00000171V02GX.html).

    Result
    Result
    		Proceed to
    DTC is not output
    		A
    DTC is output (for LHD)
    		B
    DTC is output (for RHD)
    		C


B
REPLACE MASTER CYLINDER SOLENOID (LandCruiser RM00000171U02DX.html)

C
REPLACE MASTER CYLINDER SOLENOID (LandCruiser RM00000171U02EX.html)
A

USE SIMULATION METHOD TO CHECK (LandCruiser RM000003YMJ00XX.html)