Lexus RX (RX 350L, RX450h) 2016-2024 Repair Manual: Left Rear Wheel Speed Sensor Circuit Intermittent (C050C1F)

DESCRIPTION

The speed sensor detects wheel speed and sends the appropriate signals to the skid control ECU (brake actuator assembly). These signals are used for brake control.

Speed sensor rotors have rows of alternating N and S magnetic poles, and their magnetic fields change when the rotors turn.

Each speed sensor detects that magnetic change and sends a pulse signal to the skid control ECU (brake actuator assembly).

HINT:

When the connectors between the speed sensor and skid control ECU (brake actuator assembly) are connected, the following waveform is output.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
C050C1F	Left Rear Wheel Speed Sensor Circuit Intermittent	Any of the following is detected: When the +BS terminal voltage is 17.4 V or less, an open in the sensor signal circuit of a malfunctioning area occurs 255 times or more. When the +BS terminal voltage is 17.4 V or less at a vehicle speed of 20 km/h (12 mph) or more, noise occurs in the sensor signals of a malfunctioning wheel 75 times or more within 5 seconds. When the +BS terminal voltage is 17.4 V or less at a vehicle speed of 10 km/h (6 mph) or more, noise occurs once per rotor rotation for 15 seconds or more.	Rear speed sensor LH*1 Rear speed sensor LH (rear axle hub and bearing assembly LH)*2 Sensor installation Rear skid control sensor wire LH No. 1*2 Rear skid control sensor wire LH No. 2*3 Wire harness and connector Rear speed sensor rotor LH (rear axle hub and bearing assembly LH)*2 Skid control ECU (brake actuator assembly)

DTC Detection Conditions: C050C1F

		Vehicle Condition
		Pattern 1	Pattern 2	Pattern 3
Diagnosis Condition	When the +BS terminal voltage is 17.4 V or less	○	-	-
	When the +BS terminal voltage is 17.4 V or less at a vehicle speed of 10 km/h (6 mph) or more	-	-	○
	When the +BS terminal voltage is 17.4 V or less at a vehicle speed of 20 km/h (12 mph) or more	-	○	-
Malfunction Status	An open in the sensor signal circuit of a malfunctioning area occurs 255 times or more	○	-	-
	Noise occurs in the sensor signals of a malfunctioning wheel 75 times or more within 5 seconds	-	○	-
	Noise occurs once per rotor rotation	-	-	○
Detection Time		-	-	15 seconds or more
Number of Trips		1 trip	1 trip	1 trip

HINT:

DTC will be output when conditions for any of the patterns in the table above are met.

WIRING DIAGRAM

w/o AVS (for AWD) w/o AVS (for 2WD) w/ AVS (for AWD) w/ AVS (for 2WD)

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
RL Speed Sensor Voltage Open	Rear speed sensor LH voltage open detection	Under intermittent / Normal	Under intermittent: Momentary interruption detected Normal: Momentary interruption not detected	-

Chassis > Brake/EPB > Data List

Tester Display
RL Speed Sensor Voltage Open

(d) Select the line graph display.

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

Click here

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 (RL 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
RL Wheel Speed	Rear 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
RL 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.

Click here

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 C050C1F is not output.	A
DTC C050C1F 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
for AWD	A
for 2WD	B

B

GO TO STEP 14

A

6.	CHECK REAR SPEED SENSOR LH INSTALLATION

(a) Turn the engine switch off.

*1 Rear Speed Sensor LH *a Correct *b Incorrect *c 8.5 Nm *d No clearance

(b) Check the rear speed sensor LH installation.

OK:

There is no clearance between the rear speed sensor LH and rear axle carrier sub-assembly LH.

The installation bolt is tightened properly.

Torque

8.5 N*m (87 kgf*cm, 75 in.*lbf)

NG

REINSTALL OR REPLACE REAR SPEED SENSOR LH

OK

7.	CHECK REAR SPEED SENSOR LH AND REAR SPEED SENSOR ROTOR LH (CHECK FOR FOREIGN MATTER)

(a) Remove the rear speed sensor LH and the component with the rear speed sensor rotor LH.

for rear speed sensor LH: Click here

for rear speed sensor rotor LH: Click here

(b) Check the rear speed sensor LH tip and rear speed sensor rotor LH.

OK:

No scratches, oil, or foreign matter on the rear speed sensor LH tip and rear speed sensor rotor LH.

NG

CLEAN OR REPLACE REAR SPEED SENSOR LH OR COMPONENT WITH REAR SENSOR ROTOR LH

OK

8.	CHECK VEHICLE SPECIFICATION

(a) Check the vehicle specification.

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

B

GO TO STEP 11

A

9.	CHECK HARNESS AND CONNECTOR (REAR SPEED SENSOR 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) Disconnect the T1 rear speed sensor 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
T1-3 (RL+) - A41-5 (RL+)	Always	Below 1 Ω
T1-3 (RL+) or A41-5 (RL+) - Body ground	Always	10 kΩ or higher
T1-1 (RL-) - A41-4 (RL-)	Always	Below 1 Ω
T1-1 (RL-) or A41-4 (RL-) - 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 wire harness connector (to Rear 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
T1-3 (RL+) - Body ground	Engine switch on (IG)	11 to 14 V

OK

REPLACE REAR SPEED SENSOR LH

NG

REPLACE BRAKE ACTUATOR ASSEMBLY

11.	INSPECT REAR SKID CONTROL SENSOR WIRE LH NO. 2

(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.

*a Front view of rear skid control sensor wire LH No. 2 *b (to Sensor Side Connector) *c (to Vehicle Side Connector)

(b) Disconnect the z23 and T8 rear skid control sensor wire LH No. 2 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
z23-1 (RL+) - T8-3 (RL+)	Always	Below 1 Ω
z23-1 (RL+) or T8-3 (RL+) - Body ground and other terminals	Always	10 kΩ or higher
z23-3 (RL-) - T8-1 (RL-)	Always	Below 1 Ω
z23-3 (RL-) or T8-1 (RL-) - Body ground and other terminals	Always	10 kΩ or higher

NG

REPLACE REAR SKID CONTROL SENSOR WIRE LH NO. 2

OK

12.	INSPECT HARNESS AND CONNECTOR (REAR SKID CONTROL SENSOR WIRE LH NO. 2 - 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
T8-3 (RL+) - A41-5 (RL+)	Always	Below 1 Ω
T8-3 (RL+) or A41-5 (RL+) - Body ground	Always	10 kΩ or higher
T8-1 (RL-) - A41-4 (RL-)	Always	Below 1 Ω
T8-1 (RL-) or A41-4 (RL-) - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

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

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

*a Front view of rear skid control sensor wire LH No. 2 (to Rear Speed Sensor LH)

(b) Reconnect the T8 rear skid control sensor wire LH No. 2 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
z23-1 (RL+) - Body ground	Engine switch on (IG)	11 to 14 V

OK

REPLACE REAR SPEED SENSOR LH

NG

REPLACE BRAKE ACTUATOR ASSEMBLY

14.	CHECK REAR SPEED SENSOR LH INSTALLATION

(a) Turn the engine switch off.

*a Correct *b Incorrect *c No clearance

(b) Check the rear speed sensor LH installation.

OK:

There is no clearance between the rear speed sensor LH and the rear axle hub and bearing assembly LH.

HINT:

The rear speed sensor rotor LH and rear speed sensor LH are incorporated into the rear axle hub and bearing assembly LH.

If the rear speed sensor rotor LH needs to be replaced, replace the rear axle hub and bearing assembly LH with rear speed sensor LH.

NG

REPLACE REAR AXLE HUB AND BEARING ASSEMBLY LH

OK

15.	CHECK VEHICLE SPECIFICATION

(a) Check the vehicle specification.

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

B

GO TO STEP 19

A

16.	INSPECT REAR SKID CONTROL SENSOR WIRE LH NO. 1

(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.

*a Front view of rear skid control sensor wire LH No. 1 *b (to Sensor Side Connector) *c (to Vehicle Side Connector)

(b) Disconnect the j2 and Tj2 rear skid control sensor wire LH No. 1 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
j2-2 (RL+) - Tj2-3 (RL+)	Always	Below 1 Ω
j2-2 (RL+) or Tj2-3 (RL+) - Body ground and other terminals	Always	10 kΩ or higher
j2-1 (RL-) - Tj2-1 (RL-)	Always	Below 1 Ω
j2-1 (RL-) or Tj2-1 (RL-) - Body ground and other terminals	Always	10 kΩ or higher

NG

REPLACE REAR SKID CONTROL SENSOR WIRE LH NO. 1

OK

17.	CHECK HARNESS AND CONNECTOR (REAR SKID CONTROL SENSOR WIRE LH NO. 1 - 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
Tj2-3 (RL+) - A41-5 (RL+)	Always	Below 1 Ω
Tj2-3 (RL+) or A41-5 (RL+) - Body ground	Always	10 kΩ or higher
Tj2-1 (RL-) - A41-4 (RL-)	Always	Below 1 Ω
Tj2-1 (RL-) or A41-4 (RL-) - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

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

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

*a Front view of rear skid control sensor wire LH No. 1 (to Rear Speed Sensor LH (Rear Axle Hub and Bearing Assembly LH))

(b) Reconnect the Tj2 rear skid control sensor wire LH No. 1 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
j2-2 (RL+) - Body ground	Engine switch on (IG)	11 to 14 V

HINT:

The rear speed sensor LH is incorporated into the rear axle hub and bearing assembly LH.

If the rear speed sensor LH needs to be replaced, replace the rear axle hub and bearing assembly LH.

OK

REPLACE REAR AXLE HUB AND BEARING ASSEMBLY LH

NG

REPLACE BRAKE ACTUATOR ASSEMBLY

19.	INSPECT REAR SKID CONTROL SENSOR WIRE LH NO. 1

(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.

*a Front view of rear skid control sensor wire LH No. 1 *b (to Sensor Side Connector) *c (to Vehicle Side Connector)

(b) Disconnect the j2 and j6 rear skid control sensor wire LH No. 1 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
j2-2 (RL+) - j6-1 (RL+)	Always	Below 1 Ω
j2-2 (RL+) or j6-1 (RL+) - Body ground and other terminals	Always	10 kΩ or higher
j2-1 (RL-) - j6-3 (RL-)	Always	Below 1 Ω
j2-1 (RL-) or j6-3 (RL-) - Body ground and other terminals	Always	10 kΩ or higher

NG

REPLACE REAR SKID CONTROL SENSOR WIRE LH NO. 1

OK

20.	INSPECT REAR SKID CONTROL SENSOR WIRE LH NO. 2

(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.

*a Front view of rear skid control sensor wire LH No. 2 *b (to Sensor Side Connector) *c (to Vehicle Side Connector)

(b) Disconnect the T8 rear skid control sensor wire LH No. 2 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
j6-1 (RL+) - T8-3 (RL+)	Always	Below 1 Ω
j6-1 (RL+) or T8-3 (RL+) - Body ground and other terminals	Always	10 kΩ or higher
j6-3 (RL-) - T8-1 (RL-)	Always	Below 1 Ω
j6-3 (RL-) or T8-1 (RL-) - Body ground and other terminals	Always	10 kΩ or higher

NG

REPLACE REAR SKID CONTROL SENSOR WIRE LH NO. 2

OK

21.	CHECK HARNESS AND CONNECTOR (REAR SKID CONTROL SENSOR WIRE LH NO. 2 - 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
T8-3 (RL+) - A41-5 (RL+)	Always	Below 1 Ω
T8-3 (RL+) or A41-5 (RL+) - Body ground	Always	10 kΩ or higher
T8-1 (RL-) - A41-4 (RL-)	Always	Below 1 Ω
T8-1 (RL-) or A41-4 (RL-) - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

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

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

*a Front view of rear skid control sensor wire LH No. 1 (to Rear Speed Sensor LH (Rear Axle Hub and Bearing Assembly LH))

(b) Reconnect the j6 and T8 rear skid control sensor wire LH No. 2 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
j2-2 (RL+) - Body ground	Engine switch on (IG)	11 to 14 V

HINT:

The rear speed sensor LH is incorporated into the rear axle hub and bearing assembly LH.

If the rear speed sensor LH needs to be replaced, replace the rear axle hub and bearing assembly LH.

OK

REPLACE REAR AXLE HUB AND BEARING ASSEMBLY LH

NG

REPLACE BRAKE ACTUATOR ASSEMBLY