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

CAUTION / NOTICE / HINT

HINT:

*: Use the Techstream.

PROCEDURE

1.

VEHICLE BROUGHT TO WORKSHOP

NEXT

2.

CUSTOMER PROBLEM ANALYSIS

NEXT

3.

CONNECT TECHSTREAM TO DLC3*

HINT:

If the display indicates a communication malfunction, inspect the DLC3.

When any CAN communication system DTCs are output, perform troubleshooting on the CAN communication system first.

NEXT

4.

CHECK DTC AND FREEZE FRAME DATA*

(a) Check for DTCs.

Click here

Powertrain > Engine > Trouble Codes

(b) Check for freeze frame data.

Click here

HINT:

Record or print DTCs and freeze frame data if necessary.

NEXT

5.

CLEAR DTC AND FREEZE FRAME DATA*

(a) Clear the DTCs and freeze frame data.

Click here

Powertrain > Engine > Clear DTCs
NEXT

6.

CONDUCT VISUAL INSPECTION

NEXT

7.

SELECT CHECK MODE DIAGNOSIS*

(a) Switch the ECM from normal mode to check mode.

Click here

Powertrain > Engine > Utility

Tester Display

Check Mode

NEXT

8.

CONFIRM PROBLEM SYMPTOMS

(a) Confirm problem symptoms.

HINT:

If the engine does not start, first perform the "Check DTC" procedure and "Conduct Basic Inspection" procedure below.

Result

Proceed to

Malfunction does not occur

A

Malfunction occurs

B

B

GO TO STEP 10

A

9.

SIMULATE SYMPTOMS

HINT:

Refer to Symptom Simulation.

Click here

NEXT

10.

CHECK DTC*

(a) Check for DTCs.

Click here

Powertrain > Engine > Trouble Codes

Result

Proceed to

DTCs are output

A

DTCs are not output

B

B

GO TO STEP 12

A

11.

REFER TO DTC CHART

HINT:

Refer to Diagnostic Trouble Code Chart.

Click here

NEXT

12.

CONDUCT BASIC INSPECTION

(a) Conduct basic inspection.

Click here

Result

Proceed to

Malfunctioning parts not confirmed

A

Malfunctioning parts confirmed

B

B

GO TO STEP 17

A

13.

REFER TO PROBLEM SYMPTOMS TABLE

HINT:

Refer to Problem Symptoms Table.

Click here

Result

Proceed to

Malfunctioning circuit confirmed

A

Malfunctioning parts confirmed

B

B

GO TO STEP 17

A

14.

CHECK ECM POWER SOURCE CIRCUIT

(a) Check the ECM power source circuit.

Click here

NEXT

15.

CONDUCT CIRCUIT INSPECTION

Result

Proceed to

Malfunction not confirmed

A

Malfunction confirmed

B

B

GO TO STEP 18

A

16.

CHECK FOR INTERMITTENT PROBLEMS

(a) Check for intermittent problems.

Click here

NEXT

17.

CONDUCT PARTS INSPECTION

NEXT

18.

IDENTIFY PROBLEM

NEXT

19.

ADJUST AND/OR REPAIR

NEXT

20.

CONDUCT CONFIRMATION TEST

NEXT

END

    System Diagram
    SYSTEM DIAGRAM ...

    Check For Intermittent Problems
    CHECK FOR INTERMITTENT PROBLEMS HINT: Inspect the vehicle ECM using check mode. Intermittent problems are easier to detect with the Techstream when the ECM is in check mode. In check mode, the ECM use ...

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    Lexus RX (RX 350L, RX450h) 2016-{YEAR} Owners Manual

    Lexus RX (RX 350L, RX450h) 2016-{YEAR} Repair Manual

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