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 (master cylinder solenoid).

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

INSPECTION PROCEDURE

NOTICE:

After replacing the master cylinder solenoid, perform zero point calibration ().

HINT:

Remove the hydraulic brake booster assembly before the inspection (for LHD: , for RHD: ).

1.CHECK CONNECTION OF PUMP MOTOR WIRE HARNESS

Remove the hydraulic brake booster assembly (for LHD: , for RHD: ).

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: , for RHD: ).

OK:
The harness is tightened to the specified torque.

NG

RETIGHTEN SCREWS

OK

2.CHECK RESISTANCE OF PUMP MOTOR WIRE HARNESS

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

Dtc C1251 Open In Pump Motor Circuit. BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

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 ()

for RHD ()

NG

REPLACE BRAKE BOOSTER WITH ACCUMULATOR PUMP ASSEMBLY

OK

3.RECONFIRM DTC

Reassemble the hydraulic brake booster assembly (for LHD: , for RHD: ).

Install the hydraulic brake booster assembly (for LHD: , for RHD: ).

Clear the DTCs ().

Turn the ignition switch off.

Check if the same DTC is output ().

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 ()

C

REPLACE MASTER CYLINDER SOLENOID ()

A

CHECK FOR INTERMITTENT PROBLEMS ()

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS

Land Cruiser URJ200 URJ202 GRJ200 VDJ200

ANTI-LOCK BRAKE SYSTEM

Tester Connection	Condition	Specified Condition
Red wire terminal - Black wire terminal	Always	Below 2 Ω