Lexus NX: On-vehicle Inspection

ON-VEHICLE INSPECTION

PROCEDURE

1. INSPECT STOP LIGHT CONTROL ECU ASSEMBLY

(a) Disconnect the stop light control ECU assembly connector.

*a

Front view of wire harness connector

(to Stop Light Control ECU Assembly)

(b) Measure the voltage and resistance on the wire harness side connector according to the value (s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

A3-4 (ESS1) - A3-8 (GND)

Power switch on (IG)

11 to 14 V

A3-6 (+B) - A3-8 (GND)

Power switch off

11 to 14 V

A3-9 (ACC) - A3-8 (GND)

Power switch on (IG)

11 to 14 V

Standard Resistance:

Tester Connection

Condition

Specified Condition

A3-8 (GND) - Body ground

Always

Below 1 Ω

If the result is not as specified, repair or replace the wire harness or connector.

(c) Reconnect the stop light control ECU assembly connector.

(d) Measure the voltage according to the value (s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

A3-1 (OUT) - A3-8 (GND)

Brake pedal not depressed → pressed

Below 0 to 1.5 V → 7.5 to 14 V

A3-5 (STP) - A3-8 (GND)

Brake pedal not depressed → pressed

Below 0 to 1.5 V → 7.5 to 14 V

If the result is not as specified, replace the stop light control ECU assembly.

*a

Component with harness connected

(Stop Light Control ECU Assembly)

READ NEXT:

 Removal

REMOVAL PROCEDURE 1. REMOVE DOOR SCUFF PLATE ASSEMBLY LH Click here 2. REMOVE COWL SIDE TRIM BOARD LH Click here 3. REMOVE INSTRUMENT SIDE PANEL LH Click here 4. REMOVE NO. 1 INSTRUMENT

 Installation

INSTALLATION PROCEDURE 1. INSTALL STOP LIGHT CONTROL ECU ASSEMBLY (a) Attach the clamp to install the stop light control ECU assembly. (b) Connect the connector. 2. INSTALL LOWER NO. 1 INSTRUMENT PANE

 Stop Light Switch

SEE MORE:

 Precaution

PRECAUTION CAUTION: While the auxiliary battery is connected, even if the power switch is off, the brake control system activates when the brake pedal is depressed or the door courtesy switch is turned on. Therefore, during servicing of the brake system components, do not depress the brake pedal

 Lost Communication with Front Panel LIN (B14B2)

DESCRIPTION The air conditioning control assembly communicates with the air conditioning amplifier assembly through the LIN communication system. If the LIN communication system malfunctions, the air conditioning amplifier assembly does not operate even if the air conditioning control assembly is op

© 2016-2025 Copyright www.lexunx.com