Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Left Front Wheel Speed Sensor Circuit Short to Ground or Open (C050014)

DESCRIPTION

Refer to DTC C05001F.

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DTC No.	Detection Item	DTC Detection Condition	Trouble Area
C050014	Left Front Wheel Speed Sensor Circuit Short to Ground or Open	An open in the speed sensor signal circuit continues for 0.5 seconds or more.	Front speed sensor LH Front skid control sensor wire LH* Wire harness and connector Skid control ECU (brake actuator assembly)

*: w/ AVS

WIRING DIAGRAM

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CAUTION / NOTICE / HINT

PROCEDURE

1.	READ VALUE USING TECHSTREAM (MOMENTARY INTERRUPTION)

(a) Connect the Techstream to the DLC3.

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

(c) Enter the following menus: Chassis / Brake/EPB / Data List.

Chassis > Brake/EPB > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
FL Speed Open	Front speed sensor LH open detection	Under intermittent / Normal	Under intermittent: Momentary interruption detected Normal: Momentary interruption not detected	-

Chassis > Brake/EPB > Data List

Tester Display
FL Speed Open

(d) Select the line graph display.

(e) Check for any momentary interruption in the wire harness and connector.

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OK:

Normal (There are no momentary interruptions.)

NOTICE:

Perform the above inspection before removing the sensor and connector.

NG

GO TO STEP 5

OK

2.	READ VALUE USING TECHSTREAM (FL WHEEL SPEED)

(a) Enter the following menus: Chassis / Brake/EPB / Data List.

Chassis > Brake/EPB > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
FL Wheel Speed	Front wheel speed sensor LH reading	Min.: 0.0 km/h (0.0 mph) Max.: 6553.5 km/h (4072 mph)	Vehicle stopped: 0.0 km/h (0.0 mph)	When driving at constant speed: No large fluctuations

Chassis > Brake/EPB > Data List

Tester Display
FL Wheel Speed

(b) Start the engine.

(c) Perform a road test.

(d) Check the speed value output from the speed sensor displayed on the Techstream.

HINT:

Factors that affect the indicated vehicle speed include tire size, tire pressure, and tire wear. The speed indicated on the speedometer has an allowable margin of error. This can be tested using a speedometer tester (calibrated chassis dynamometer). For details about testing and the margin of error, see the reference chart.

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OK:

The speed value output from the speed sensor displayed on the Techstream is similar to the speed indicated on the speedometer.

NG

GO TO STEP 5

OK

3.

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

4.	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 C050014 is not output.	A
DTC C050014 is output.	B

A

USE SIMULATION METHOD TO CHECK

B

REPLACE BRAKE ACTUATOR ASSEMBLY

5.	CHECK VEHICLE SPECIFICATION

(a) Check the vehicle specification.

Result	Proceed to
w/o AVS	A
w/ AVS	B

B

GO TO STEP 8

A

6.	INSPECT HARNESS AND CONNECTOR (FRONT SPEED SENSOR LH - 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 A41 skid control ECU (brake actuator assembly) connector.

(d) Disconnect the A92 front speed sensor LH 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
A92-3 (FL+) - A41-22 (FL+)	Always	Below 1 Ω
A92-3 (FL+) or A41-22 (FL+) - Body ground	Always	10 kΩ or higher
A92-4 (FL-) - A41-21 (FL-)	Always	Below 1 Ω
A92-4 (FL-) or A41-21 (FL-) - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

7.	INSPECT BRAKE ACTUATOR ASSEMBLY (SENSOR POWER SOURCE CIRCUIT)

(a) Reconnect the A41 skid control ECU (brake actuator assembly) connector.

*a Front view of wire harness connector (to Front Speed Sensor LH)

(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) Turn the engine switch on (IG).

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A92-3 (FL+) - Body ground	Engine switch on (IG)	11 to 14 V

OK

REPLACE FRONT SPEED SENSOR LH

NG

REPLACE BRAKE ACTUATOR ASSEMBLY

8.	INSPECT FRONT SKID CONTROL SENSOR WIRE LH

(a) Turn the engine switch off.

*a Front view of front skid control sensor wire LH *b (to Sensor Side Connector) *c (to Vehicle Side Connector)

(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 z14 and A90 front skid control sensor wire LH connector.

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

OK:

No deformation or corrosion.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
z14-1 (FL+) - A90-3 (FL+)	Always	Below 1 Ω
z14-1 (FL+) or A90-3 (FL+) - Body ground and other terminals	Always	10 kΩ or higher
z14-2 (FL-) - A90-4 (FL-)	Always	Below 1 Ω
z14-2 (FL-) or A90-4 (FL-) - Body ground and other terminals	Always	10 kΩ or higher

NG

REPLACE FRONT SKID CONTROL SENSOR WIRE LH

OK

9.	CHECK HARNESS AND CONNECTOR (FRONT SKID CONTROL SENSOR WIRE LH - BRAKE ACTUATOR ASSEMBLY)

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

OK:

The connector is securely connected.

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

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

OK:

No deformation or corrosion.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A90-3 (FL+) - A41-22 (FL+)	Always	Below 1 Ω
A90-3 (FL+) or A41-22 (FL+) - Body ground	Always	10 kΩ or higher
A90-4 (FL-) - A41-21 (FL-)	Always	Below 1 Ω
A90-4 (FL-) or A41-21 (FL-) - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

10.	INSPECT BRAKE ACTUATOR ASSEMBLY (SENSOR POWER SOURCE CIRCUIT)

(a) Reconnect the A41 skid control ECU (brake actuator assembly) connector.

*a Front view of front skid control sensor wire LH (to Front Speed Sensor LH)

(b) Reconnect the A90 front skid control sensor wire LH connector.

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

OK:

The connector is securely connected.

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

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
z14-1 (FL+) - Body ground	Engine switch on (IG)	11 to 14 V

OK

REPLACE FRONT SPEED SENSOR LH

NG

REPLACE BRAKE ACTUATOR ASSEMBLY