Lexus ES300 (2002 year). Service manual — part 116

CHASSIS – BRAKE

CH-76

Self-Diagnosis

If the skid control ECU detects a malfunction in the ABS with EBD, Brake Assist, TRAC, and VSC

systems, the ABS, brake system, VSC warning lights and TRAC OFF indicator light that corresponds to
the function in which the malfunction has been detected indicates or lights up, as indicated in the table
below, to alert the driver of the malfunction.

: Light ON —: Light OFF

Item

ABS

EBD

Brake

Assist

TRAC

VSC

Skid

Control

ECU

ABS Warning Light

—

—

Brake System Warning Light

—

—

—

—

TRAC OFF Indicator Light

VSC Warning Light

At the same time, the DTCs (Diagnosis Trouble Codes) are stored in memory. The DTCs can be read by

connecting the SST (09843-18040) between the Tc and CG terminals DLC3 and observing the blinking
of the ABS warning light and VSC warning light, or by connecting a hand-held tester.

This system has a sensor signal check function. The DTCs can be read by connecting the SST

(09843-18040) between the Tc and CG terminals of DLC3 and observing the blinking of the ABS warning
light and VSC warning light after check function, or by connecting a hand-held tester.

The DLC1 has been discontinued.
The following DTCs have been added to the ABS & Brake Assist & VSC system of the ’01 ES300 model:

Output by blinking ABS warning light

DTC No.

Detection Item

C1235 / 35 Foreign matter is attached on the tip of the right front sensor

C1236 / 36 Foreign matter is attached on the tip of the left front sensor

C1238 / 38 Foreign matter is attached on the tip of the right rear sensor

C1239 / 39 Foreign matter is attached on the tip of the left rear sensor

Output by blinking VSC warning light

DTC No.

Detection Item

C1335 / 35 Malfunction in steering angle sensor input circuit

C1336 / 39 Zero point calibration of deceleration sensor undone

C1261 / 61 Malfunction in master cylinder pressure sensor

The C1207/37, C1208/72, and C1228/28 DTCs have been discontinued to the TRAC system of the

previous model.

For details on the DTCs that are stored in skid control ECU memory and the DTCs that are output through
the sensor check function, see the 2002 LEXUS ES300 Repair Manual (Pub. No. RM911U).

CHASSIS – BRAKE

CH-77

Fail-Safe

In the event of a malfunction in the TRAC and/or VSC, the skid control ECU prohibits the TRAC and

VSC operations.

In the event of a malfunction in the ABS and/or Brake Assist, the skid control ECU prohibits the ABS

with EBD, Brake Assist, TRAC, and VSC operations.

In the event of the malfunction in the EBD control, skid control ECU prohibits the EBD control. Thus,

the brake and throttle valve opening angle control will be opened in the same condition as in the condition
without the ABS with EBD, Brake Assist, TRAC, VSC.

CHASSIS – STEERING

CH-78

211CH32

STEERING

DESCRIPTION

As in the previous models, a rack and pinion type steering gear and an engine revolution sensing type

power steering are used on all model.

The power steering vane pump on ’02 ES300 has newly adopted a pressure return type vane pump which

makes the discharge pressure flow volume return at middle and high speed, thus secured the fine steering
feeling.

The stepless tilt steering is used on all models.
The steering column has adopted an energy absorbing mechanism that uses energy absorbing plate.

Specification

Gear Ratio (Overall)

16.0

No. to Turns Lock to Lock

3.06

Rack Stroke

mm (in.)

149.0 (5.87)

Fluid Type

ATF Type DEXRON



II or III

CHASSIS – STEERING

CH-79

208CH39

208CH38

’02 ES300

’01 ES300

Flow Control Valve

Orifice

Rod

Flow Control Valve

Control Spool

Orifice

208CH45

Flow Volume

(A)

(B)

(C)

(D)

(D)

Pump Speed

POWER STEERING VANE PUMP

1. Construction

In this pump, the control spool to control the pump flow volume in the middle and high range of the pump
speed has been discontinued and a rod for the flow control valve which decides the flow volume opening area
has been established instead.
Other basic structure and operation are the same as ’01 ES300.

2. Operation

Flow Volume Characteristics