Lexus RX300 (MCU15). Service manual - part 314

I00133

2

1

4

3

I00311

4

3

DI–488

–

DIAGNOSTICS

CRUISE CONTROL SYSTEM

LEXUS RX300   (RM785E)

INSPECTION PROCEDURE

1

Check stop light switch.

PREPARATION:
Disconnect the stop light switch connector.
CHECK:
Check continuity between terminals.

Switch position

Continuity

Switch pin free

(Brake pedal depressed)

1 – 2

Switch pin pushed in

(Brake pedal released)

3 – 4

NG

Replace stop light switch.

OK

2

Check resistance between terminals L and GND of actuator magnetic clutch.

PREPARATION:
(a)

Turn ignition switch OFF.

(b)

Disconnect the actuator connector.

CHECK:
Measure resistance between terminals 3 and 4.
OK:

Resistance: 34.65 – 42.35 Ω.

NG

Replace cruise control actuator.

OK

–

DIAGNOSTICS

CRUISE CONTROL SYSTEM

DI–489

LEXUS RX300   (RM785E)

3

Check for open and short in harness and connectors between cruise control
ECU and actuator magnetic clutch, actuator magnetic clutch and body ground
(See page IN–32).

NG

Repair or replace harness or connector.

OK

Check and replace cruise control ECU (See
page IN–32).

I00055

4

3

(+)

(–)

DI–490

–

DIAGNOSTICS

CRUISE CONTROL SYSTEM

LEXUS RX300   (RM785E)

DTC

14

Actuator Mechanical Malfunction

CIRCUIT DESCRIPTION

The circuit detects the rotation position of the actuator control plate and sends a signal to the ECU.

DTC No.

Detection Item

Trouble Area

14

Cruise control actuator mechanical malfunction.

S

Actuator lock: (motor, arm)

S

Actuator motor

S

Cruise control ECU

WIRING DIAGRAM

See page DI–486.

INSPECTION PROCEDURE

1

Check cruise control actuator arm locking operation

PREPARATION:
(a)

Turn ignition switch OFF.

(b)

Disconnect the actuator connector.

CHECK:
Connect the positive (+) lead from the battery to the terminal 3
of actuator and the negative (–) lead to terminal 4.
NOTICE:
Do not connect the high tension cables to the wrong bat-
tery terminal. The cruise control actuator will be damaged.
Move the control plate by hand.
OK:

Control plate doesn’t move.

NG

Replace cruise control actuator.

OK

DI08O–21

I03209

Fully open side

Control plate

4

3 2

1

(+)

(–)

Fully close side

Control plate

(–)

(+)

4

3

2

1

–

DIAGNOSTICS

CRUISE CONTROL SYSTEM

DI–491

LEXUS RX300   (RM785E)

2

Check cruise control actuator operation.

PREPARATION:
(a)

Turn ignition switch OFF.

(b)

Disconnect the actuator connector.

CHECK:
Connect the positive (+) lead from the battery to terminals 1 and
3 of actuator, connect the negative (–) lead to terminals 2 and
4 of actuator.
OK:

Control arm moves to fully open side

CHECK:
Connect the positive (+) lead from the battery to terminals 2 and
3 of actuator, connect the negative (–) lead to terminals 1 and
4 of actuator.
OK:

Control arm moves to fully closed side

NG

Replace cruise control actuator.

OK

3

Check harness and connector between cruise control ECU and cruise control ac-
tuator (See page IN–32).

NG

Repair or replace harness or connector.

OK

Check and replace cruise control ECU (See
page IN–32).