Lexus SC300 / Lexus SC400. Service manual - part 186

Location of Connectors in Instrument Panel

BE–374

–

BODY ELECTRICAL SYSTEM

Door Lock Control System

–

BODY ELECTRICAL SYSTEM

Door Lock Control System

BE–375

Check DOME fuse.

NG

OK

Check for short in all the harness
and components connected to the
DOME fuse (See attached wiring
diagram).

1

Check and repair harness and connector
between ECU and battery.

Proceed to next circuit inspection
shown on matrix chart (See page

BE–371

).

Repair or replace harness or
connector.

Check voltage between terminals +B1
and E of ECU connector.

Check for open in harness and connector
between ECU and body ground (See page

IN–27

).

OK

OK

NG

NG

2

3

WIRING DIAGRAM

CIRCUIT INSPECTION

ECU Power Source Circuit

     CIRCUIT DESCRIPTION

This circuit provides power to operate the theft deterrent and door lock ECU.

     DIAGNOSTIC CHART

BE–376

–

BODY ELECTRICAL SYSTEM

Door Lock Control System

OK

NG

NG

OK

OK

NG

INSPECTION PROCEDURE

1

Check DOME fuse.

C

OK

P

Remove DOME fuse from R/B No. 2.

Check continuity of DOME fuse.

Continuity

Check for short in all the harness and components con-
nected to the DOME fuse (See attached wiring diagram).

2

Check voltage between terminals +B1 and E of ECU connector.

C

OK

P

1.

Remove the No. 1 under cover and heater duct.

2.

Disconnect the theft deterrent and door lock ECU
connectors.

Measure voltage between terminals +B1 and E of ECU
connector.

Voltage:

10 – 14 V

Proceed to next circuit inspection shown on matrix chart
(See page 

BE–371

).

3

Check for open in harness and connector between ECU and body ground (See page 

IN–27

).

Repair or replace harness or connector.

Check and repair harness and connector between
ECU and battery.

–

BODY ELECTRICAL SYSTEM

Door Lock Control System

BE–377