Lexus NX: Operating Light Control Rheostat does not Change Light Brightness

Lexus NX Service Manual / Vehicle Interior / Meter / Gauge / Display / Meter / Gauge System / Operating Light Control Rheostat does not Change Light Brightness

DESCRIPTION

The combination meter assembly receives signals from this circuit to adjust the illumination of the combination meter assembly. The combination meter assembly sets the illumination level based on the user operation of the light control rheostat switch in the trip switch.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When replacing the combination meter assembly, make sure to replace it with a new one.

HINT:

  • The meter illumination level can be adjusted by pressing the light control rheostat switch.
  • The meter illumination dims when the taillights are turned on.
  • Setting the meter illumination to maximum brightness cancels the above dimming of the meter illumination.

PROCEDURE

1.

READ VALUE USING TECHSTREAM (LIGHT CONTROL UP SWITCH, LIGHT CONTROL DOWN SWITCH)

(a) Using the Techstream, read the Data List.

Click here

Body Electrical > Combination Meter > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Light Control Up Switch

Light control rheostat up switch

OFF or ON

OFF: Light control rheostat up switch released

ON: Light control rheostat up switch pressed

-

Light Control Down Switch

Light control rheostat down switch

OFF or ON

OFF: Light control rheostat down switch released

ON: Light control rheostat down switch pressed

-

Body Electrical > Combination Meter > Data List

Tester Display

Light Control Up Switch

Light Control Down Switch

OK:

Light control rheostat up or down switch condition displayed on the Techstream changes with the actual switch operation.

OK

REPLACE COMBINATION METER ASSEMBLY

NG

2.

INSPECT TRIP SWITCH

(a) Remove the trip switch.

Click here

(b) Inspect the trip switch.

Click here

NG

REPLACE TRIP SWITCH

OK

3.

CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - TRIP SWITCH)

(a) Disconnect the I10 combination meter assembly connector.

(b) Disconnect the I1 trip switch connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

I10-25 (TR) - I1-2 (RV)

Always

Below 1 Ω

I10-26 (SW3) - I1-5 (E)

Always

Below 1 Ω

I10-25 (TR) or I1-2 (RV) - Body ground

Always

10 kΩ or higher

I10-26 (SW3) or I1-5 (E) - Body ground

Always

10 kΩ or higher

OK

REPLACE COMBINATION METER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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