Lexus SC300 / Lexus SC400. Manual - part 183

DESCRIPTION

The door lock control system has a key–interlocked door lock and unlock function and a key–confinement pre-
vention function. All doors can be locked and unlocked simultaneously by key operation at the front right or left
door (the key needs to be operated twice to unlock the doors at the driver’s door). If the door lock operation is
performed when one of the doors is open and the ignition key inserted in the key cylinder, doors are unlocked
automatically to prevent the ignition key from being left inside the vehicle. The luggage compartment door can
be opened by electromagnetic opener.
For the function of component parts of this system, refer to the circuit description in circuit inspection.

PARTS LOCATION

BE–362

–

BODY ELECTRICAL SYSTEM

Door Lock Control System

–MEMO–

–

BODY ELECTRICAL SYSTEM

Door Lock Control System

BE–363

HOW TO PROCEED WITH TROUBLESHOOTING

Perform troubleshooting in accordance with the procedure on the following page.

  CUSTOMER PROBLEM ANALYSIS

Using the customer problem analysis check sheet for reference, ask the customer in as much detail as
possible about the problem.



 PROBLEM 

SYMPTOM 

CONFIRMATION, 



 SYMPTOM SIMULATION

Confirm the problem symptoms. If the problem does not reappear, be sure to simulate the problem using
”Problem Simulation Method”.
For example, if the malfunction involves failure of the lock or unlock during operation of the Door Lock Con-
trol Switch, check if lock and unlock operation of the door using the key is normal or abnormal, and also
check if key confinement prevention function and luggage compartment door opener function are normal
or not. And having fully checked the extent of the malfunction.



  MATRIX CHART OF PROBLEM SYMPTOMS

Confirm the order of inspection for each applicable problem symptom on the matrix chart.



 CIRCUIT 

INSPECTION

Proceed with diagnosis of each circuit in accordance with the inspection order confirmed in 



. Judge

whether the cause of the problem is in the sensor, wire harness and connectors, or the ECU.



 REPAIR

When the cause of the problem is found in 



, perform repairs.



 CONFIRMATION 

TEST

After 

completing repairs, confirm that the problem is eliminated and that all functions of the door lock control

system are normal.

BE–364

–

BODY ELECTRICAL SYSTEM

Door Lock Control System

Vehicle Brought to Workshop

Problem does
not occur

Problem
occurs

Customer Problem Analysis

Problem Symptom Confirmation

Matrix Chart of Problem Symptoms

P. 

BE–371

Symptom Simulation

P. 

IN–20

Chart Inspection

P. 

BE–376

 ~ P. 

BE–392

Identification of Problem

Repair

Confirmation Test

End

Item inside        are titles of pages in this manu-
al, with the page number indicated in the bottom
portion. See the indicated pages for detailed
explanations.

P. 

BE–366

–

BODY ELECTRICAL SYSTEM

Door Lock Control System

BE–365