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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: RM000001DXN00LX
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DESCRIPTION (2008 LX570)

DTC

C1253/53

Pump Motor Relay Malfunction

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

C1253/53

There is a motor system circuit (motor input circuit) malfunction.
  • Hydraulic brake booster pump motor
  • Hydraulic brake booster pump motor circuit

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

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

PROCEDURE

1.

PERFORM ACTIVE TEST USING TECHSTREAM (MOTOR RELAY)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG) and turn the Techstream on.

(c) Start the engine.

(d) Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test.

ABS/VSC/TRAC

Tester Display

Test Part

Control Range

Diagnostic Note

Motor Relay

Motor relay

Relay ON/OFF

An operation sound of the motor can be heard.

(e) Check the operation sound of the motor individually when operating it with the Techstream.

OK:

The operation sound of the motor can be heard.

OK

2.

RECONFIRM DTC

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

(b) Turn the engine switch off.

(c) Depress the brake pedal more than 20 times.

(d) Turn the engine switch on (IG).

(e) Wait until the pump motor stops.

(f) Depress the brake pedal several times until the pump motor turns on. (Procedure A)

(g) Wait until the pump stops. (Procedure B)

(h) Repeat the above steps (procedure A and B) 3 more times.

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

HINT:

Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

Result

Result

Proceed to

DTC is output.

A

DTC is not output.

B
A

3.

INSPECT SKID CONTROL ECU (+BM TERMINAL)

(a) Disconnect the A24 and A25 skid control ECU connectors.

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

A24-2 (+BM1) - Body ground

Always

11 to 14 V

A25-2 (+BM2) - Body ground

Always

11 to 14 V
OK

4.

INSPECT SKID CONTROL ECU (GND TERMINAL)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A24-1 (GND1) - Body ground

Always

Below 1 Ω

A24-32 (GND2) - Body ground

Always

Below 1 Ω

A25-4 (GND3) - Body ground

Always

Below 1 Ω
OK

5.

RECONFIRM DTC

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

(b) Turn the engine switch off.

(c) Depress the brake pedal more than 20 times.

(d) Turn the engine switch on (IG).

(e) Wait until the pump motor stops.

(f) Depress the brake pedal several times until the pump motor turns on. (Procedure A)

(g) Wait until the pump stops. (Procedure B)

(h) Repeat the above steps (procedure A and B) 3 more times.

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

HINT:

Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

Result

Result

Proceed to

DTC is output.

A

DTC is not output.

B
A