Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Brake Pedal Switch "A" Circuit Open (C004013)

DESCRIPTION

The brake pedal load sensing switch signal turns on when the brake pedal is depressed with a force exceeding a predetermined level.

The skid control ECU (brake actuator assembly) uses this circuit to detect if the brake pedal is depressed or not.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
C004013	Brake Pedal Switch "A" Circuit Open	When the +BS terminal voltage is from 9.5 to 17.4 V, an open or short in the brake pedal load sensing switch continues for 0.3 seconds or more.	Brake pedal load sensing switch (brake pedal support assembly) Wire harness and connector Skid control ECU (brake actuator assembly)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

After replacing the skid control ECU (brake actuator assembly), perform "Calibration".

Click here

PROCEDURE

1.	READ VALUE USING TECHSTREAM (BRAKE PEDAL LOAD SENSING SW)

(a) Connect the Techstream to the DLC3.

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

(c) Select the Data List using the Techstream.

Click here

Chassis > Brake/EPB > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Brake Pedal Load Sensing SW	Brake pedal load sensing switch	OFF / ON	OFF: Brake pedal released ON: Brake pedal depressed	-

Chassis > Brake/EPB > Data List

Tester Display
Brake Pedal Load Sensing SW

(d) Check that the brake pedal load sensing switch display observed on the Techstream changes according to brake pedal operation.

OK:

The Techstream displays OFF / ON according to brake pedal operation.

NG

GO TO STEP 4

OK

2.

CLEAR DTC

(a) Operate the Techstream to clear the codes. Enter the following menus: Chassis / Brake/EPB / Trouble Codes.

Chassis > Brake/EPB > Clear DTCs

(b) Press the DTC clear button.

(c) Turn the engine switch off.

NEXT

3.	RECONFIRM DTC

(a) Start the engine.

(b) Perform a road test.

(c) Read the DTCs following the prompts on the Techstream. Enter the following menus: Chassis / Brake/EPB / Trouble Codes.

Chassis > Brake/EPB > Trouble Codes

(d) Check if the same DTC is output.

Result	Proceed to
DTC C004013 is not output.	A
DTC C004013 is output.	B

A

USE SIMULATION METHOD TO CHECK

B

REPLACE BRAKE ACTUATOR ASSEMBLY

4.	CHECK HARNESS AND CONNECTOR (BRAKE PEDAL SUPPORT ASSEMBLY - BRAKE ACTUATOR ASSEMBLY)

(a) Turn the engine switch off.

(b) Make sure that there is no looseness at the locking part and the connecting part of the connectors.

OK:

The connector is securely connected.

(c) Disconnect the A51 brake pedal load sensing switch (brake pedal support assembly) connector.

(d) Disconnect the A41 skid control ECU (brake actuator assembly) connector.

(e) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A51-2 (FSW+) - A41-28 (FSW+)	Always	Below 1 Ω
A51-2 (FSW+) or A41-28 (FSW+) - Body ground	Always	10 kΩ or higher
A51-1 (FSW-) - Body ground	1 minute or more after disconnecting the cable from the negative (-) battery terminal	Below 1 Ω

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

5.	INSPECT BRAKE PEDAL SUPPORT ASSEMBLY

(a) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition 2 (FSW+) - 1 (FSW-) Brake pedal load sensing switch off (Brake pedal depressed) 950 to 1050 Ω 2 (FSW+) - 1 (FSW-) Brake pedal load sensing switch on (Brake pedal released) 203 to 223 Ω NOTICE: Do not remove the brake pedal load sensing switch from the brake pedal support assembly. When there is a malfunction in the brake pedal load sensing switch, replace the brake pedal support assembly.

*a Component without harness connected (Brake Pedal Load Sensing Switch (Brake Pedal Support Assembly))

OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPLACE BRAKE PEDAL SUPPORT ASSEMBLY