Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: How To Proceed With Troubleshooting

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Vehicle Exterior / Lighting (ext) / Lighting System (w/ Automatic Headlight Beam Level Control System) / How To Proceed With Troubleshooting

CAUTION / NOTICE / HINT

HINT:

  • Use the following procedure to troubleshoot the lighting system.
  • *: Use the Techstream.

PROCEDURE

1.

VEHICLE BROUGHT TO WORKSHOP
NEXT

2.

CUSTOMER PROBLEM ANALYSIS

HINT:

  • In troubleshooting, confirm that the problem symptoms have been accurately identified. Preconceptions should be discarded in order to make an accurate judgment. To clearly understand what the problem symptoms are, it is extremely important to ask the customer about the problem and the conditions at the time the malfunction occurred.
  • Gather as much information as possible for reference. Past problems that seem unrelated may also help in some cases.
  • The following 5 items are important points for problem analysis:

    What

    Vehicle model, system name

    When

    Date, time, occurrence frequency

    Where

    Road conditions

    Under what conditions?

    Driving conditions, weather conditions

    How did it happen?

    Problem symptoms
NEXT

3.

PRE-CHECK

(a) Measure the battery voltage.

Standard Voltage:

11 to 14 V

If the voltage is below 11 V, recharge or replace the battery before proceeding to the next step.

(b) Check the fuses and relays.

(c) Check the connector connections and terminals to make sure that there are no abnormalities such as loose connections, deformation, etc.

NEXT

4.

CHECK COMMUNICATION FUNCTION OF CAN COMMUNICATION SYSTEM*

(a) Using the Techstream, check for CAN communication system DTCs.

Click here

Result

Proceed to

CAN DTCs are not output (for Multiple Beam Headlight)

A

CAN DTCs are not output (for Single Beam Headlight)

B

CAN DTCs are output

C
B

GO TO STEP 7

C

GO TO CAN COMMUNICATION SYSTEM

A

5.

CHECK FOR DTC*

(a) Check for DTCs.

Body Electrical > Main Body > Trouble Codes Body Electrical > AFS > Trouble Codes

Result

Proceed to

DTCs are not output (w/ Automatic High Beam System)

A

DTCs are not output (w/o Automatic High Beam System)

B

DTCs are output

C
B

GO TO STEP 9

C

GO TO DIAGNOSTIC TROUBLE CODE CHART

A

6.

CHECK FOR DTC*

(a) Check for DTCs.

Body Electrical > Front Recognition Camera (Front Lighting Control) > Trouble Codes

Result

Proceed to

DTCs are not output

A

DTCs are output

B
A

GO TO STEP 9

B

GO TO DIAGNOSTIC TROUBLE CODE CHART

7.

CHECK FOR DTC*

(a) Check for DTCs.

Body Electrical > Main Body > Trouble Codes Body Electrical > HL AutoLeveling > Trouble Codes

Result

Proceed to

DTCs are not output (w/ Automatic High Beam System)

A

DTCs are not output (w/o Automatic High Beam System)

B

DTCs are output

C
B

GO TO STEP 9

C

GO TO DIAGNOSTIC TROUBLE CODE CHART

A

8.

CHECK FOR DTC*

(a) Check for DTCs.

Body Electrical > Front Recognition Camera (Front Lighting Control) > Trouble Codes

Result

Proceed to

DTCs are not output

A

DTCs are output

B
B

GO TO DIAGNOSTIC TROUBLE CODE CHART

A

9.

CHECK VEHICLE CONTROL HISTORY*

(a) Using the Techstream, check for Vehicle Control History (RoB).

Body Electrical > Front Recognition Camera (Front Lighting Control) > Utility

Tester Display

Vehicle Control History (RoB)

NOTICE:

Make sure to record the output Vehicle Control History.

Result

Proceed to

Vehicle Control History codes are not output

A

Vehicle Control History code X2020 and/or X204D is output

B

Vehicle Control History codes other than X2020 and X204D are output

C
B

GO TO VEHICLE CONTROL HISTORY (Check Details of Code X2020 or X204D)

C

GO TO STEP 14

A

10.

PROBLEM SYMPTOMS TABLE

(a) Refer to Problem Symptoms Table.

Click here

Result

Proceed to

Fault is not listed in Problem Symptoms Table

A

Fault is listed in Problem Symptoms Table

B
B

GO TO PROBLEM SYMPTOMS TABLE

A

11.

OVERALL ANALYSIS AND TROUBLESHOOTING*

(a) Operation Check.

Click here

(b) Terminals of ECU.

Click here

(c) Data List / Active Test.

Click here

(d) On-vehicle Inspection.

(e) Inspection.

NEXT

12.

ADJUST, REPAIR OR REPLACE
NEXT

13.

CONFIRMATION TEST
NEXT

END

14.

CHECK VEHICLE CONTROL HISTORY*

(a) Clear Vehicle Control History

(1) Clear the Vehicle Control History.

Body Electrical > Front Recognition Camera (Front Lighting Control) > Utility

Tester Display

Vehicle Control History (RoB)

(b) Check Vehicle Control History

(1) Using the Techstream, check the Vehicle Control History (RoB).

Body Electrical > Front Recognition Camera (Front Lighting Control) > Utility

Tester Display

Vehicle Control History (RoB)

Result

Proceed to

Vehicle Control History (RoB) codes are not output

A

Vehicle Control History (RoB) codes are output

B
A

USE SIMULATION METHOD TO CHECK

B

GO TO VEHICLE CONTROL HISTORY

    Parts Location
    PARTS LOCATION ILLUSTRATION *A w/ Automatic High Beam System *B w/ Front Fog Light *1 HEADLIGHT ASSEMBLY LH - NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT UNIT LH *2 HEADLIGHT A ...

    Operation Check
    OPERATION CHECK AUTOMATIC LIGHT CONTROL SYSTEM OPERATION CHECK NOTICE: Make sure that the customize settings are set to default when performing the automatic light control system operation check. Clic ...

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