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Last Modified: 11-27-2007 1.6 C
Service Category: Brake Section: Brake Control/Dynamic Control System
Model Year: 2008 Model: LX570 Doc ID: RM000001EA700LX
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DESCRIPTION (2008 LX570)

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.

DTC Code

DTC Detection Condition

Trouble Area

C1251/51

There is an open in the motor system circuit (motor input circuit).

  • Pump motor wire harness connection
  • Brake booster with accumulator pump assembly
  • Master cylinder solenoid (Skid control ECU)

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

When replacing the master cylinder solenoid, perform zero point calibration BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: CALIBRATION (2008 LX570) .

HINT:

Remove the hydraulic brake booster assembly before the inspection BRAKE SYSTEM (OTHER): HYDRAULIC BRAKE BOOSTER: REMOVAL (2008 LX570) .

PROCEDURE

1.

CHECK CONNECTION OF PUMP MOTOR WIRE HARNESS

(a) Using a screwdriver, remove the 2 plugs from the hydraulic brake booster assembly BRAKE SYSTEM (OTHER): HYDRAULIC BRAKE BOOSTER: DISASSEMBLY (2008 LX570)+ .

(b) Check the tightening torque of the 2 screws which tighten the wire harness connecting the hydraulic brake booster assembly and brake booster pump BRAKE SYSTEM (OTHER): HYDRAULIC BRAKE BOOSTER: REASSEMBLY (2008 LX570)+ .

OK:

The harness is tightened to the specific torque.

Torque: 2.9 N·m (30 kgf·cm, 26 in·lbf)

OK

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:

Tester Connection

Condition

Specified Condition

Red wire terminal - Black wire terminal

Always

2 Ω
OK

3.

RECONFIRM DTC

(a) Reassemble the hydraulic brake booster assembly BRAKE SYSTEM (OTHER): HYDRAULIC BRAKE BOOSTER: REASSEMBLY (2008 LX570) .

(b) Install the hydraulic brake booster assembly BRAKE SYSTEM (OTHER): HYDRAULIC BRAKE BOOSTER: INSTALLATION (2008 LX570) .

(c) Clear the DTC BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DTC CHECK / CLEAR (2008 LX570) .

(d) Check if the same DTC is output BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DTC CHECK / CLEAR (2008 LX570) .

Result

Result

Proceed to

DTC is output.

A

DTC is not output.

B
A