Lexus RX (RX 350L, RX450h) 2016-2022 Repair Manual: Check Mode Procedure



(a) Check mode has a higher sensitivity to malfunctions and can detect malfunctions that normal mode cannot detect. Check mode can also detect all of the malfunctions that normal mode can detect. In check mode, DTCs are detected with 1 trip detection logic.


(a) Make sure that the following conditions are met:

(1) The battery voltage is 11 V or more.

(2) The throttle valve is fully closed.

(3) The shift lever is in P or N.

(4) The air conditioning is off.

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG).

(d) Turn the Techstream on.

(e) Enter the following menus: Powertrain / Transmission / Utility / Check Mode.

Powertrain > Transmission > Utility

Tester Display

Check Mode

(f) Change the ECM to check mode and check that the MIL flashes as shown in the illustration.


All DTCs and freeze frame data will be cleared if: 1) the Techstream is used to change the ECM from normal mode to check mode or vice versa; or 2) during check mode, the engine switch is turned from on (IG) to on (ACC) or off.

Before entering check mode, make a note of the DTCs and freeze frame data.

(g) Start the engine. The MIL should turn off after the engine starts.

(h) Perform Monitor Drive Pattern for the ECT.

Click here

(Or, simulate the conditions of the malfunction described by the customer.)

(i) After simulating the malfunction conditions, use the Techstream to check for DTCs and freeze frame data.

    Dtc Check / Clear
    DTC CHECK / CLEAR NOTICE: When the diagnosis system is changed from normal mode to check mode or vice versa, all DTCs and freeze frame data recorded in normal mode are cleared. Before changing modes, ...

    Fail-safe Chart
    FAIL-SAFE CHART Description The fail-safe function minimizes the loss of operation when a malfunction occurs in a sensor or solenoid. Fail-safe (a) Fail-safe control list: Malfunctioning Part Fun ...

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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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