Lexus RX (RX 350L, RX450h) 2016-2024 Repair Manual: Right Rear Wheel Speed Sensor Signal Stuck Low (C051223)

DESCRIPTION

Refer to DTC C05121F.

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DTC No.	Detection Item	DTC Detection Condition	Trouble Area
C051223	Right Rear Wheel Speed Sensor Signal Stuck Low	Any of the following is detected: When the +BS terminal voltage is 17.4 V or less at a vehicle speed of 10 km/h (6 mph) or more, output voltage from one of the speed sensors is less than that from the other sensors for 15 seconds or more.*2 When the +BS terminal voltage is 17.4 V or less at a vehicle speed of 10 km/h (6 mph) or more, output voltage from one of the speed sensors is less than that from the other sensors for 30 seconds or more.*1 When the +BS terminal voltage is 17.4 V or less at a vehicle speed less than 10 km/h (6 mph), output from one of the speed sensors is 0 km/h (0 mph) for 1 second or more. When the +BS terminal voltage is 17.4 V or less at a vehicle speed of 10 km/h (6 mph) or more, outputs from both rear speed sensors are 0 km/h (0 mph) for 15 seconds or more.*2 When the +BS terminal voltage is 17.4 V or less at a vehicle speed of 10 km/h (6 mph) or more, outputs from both rear speed sensors are 0 km/h (0 mph) for 15 seconds or more.*1	Rear speed sensor RH*1 Rear speed sensor RH (rear axle hub and bearing assembly RH)*2 Sensor installation Rear skid control sensor wire RH No. 1*2 Rear skid control sensor wire RH No. 2*3 Wire harness and connector Rear speed sensor rotor RH (rear axle hub and bearing assembly RH) Skid control ECU (brake actuator assembly)

DTC Detection Conditions: C051223

		Vehicle Condition
		Pattern 1	Pattern 2	Pattern 3	Pattern 4	Pattern 5
Diagnosis Condition	When the +BS terminal voltage is 17.4 V or less	○	○	○	○	○
Malfunction Status	At a vehicle speed of 10 km/h (6 mph) or more, output voltage from one of the speed sensors is less than that from the other sensors*2	○	-	-	-	-
	At a vehicle speed of 10 km/h (6 mph) or more, output voltage from one of the speed sensors is less than that from the other sensors*1	-	○	-	-	-
	At a vehicle speed less than 10 km/h (6 mph), output from one of the speed sensors is 0 km/h (0 mph)	-	-	○	-	-
	At a vehicle speed of 10 km/h (6 mph) or more, outputs from both rear speed sensors are 0 km/h (0 mph)*2	-	-	-	○	-
	At a vehicle speed of 10 km/h (6 mph) or more, outputs from both rear speed sensors are 0 km/h (0 mph)*1		-	-	-	○
Detection Time		15 seconds or more	30 seconds or more	1 second or more	15 seconds or more	30 seconds or more
Number of Trips		1 trip	1 trip	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

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CAUTION / NOTICE / HINT

PROCEDURE

1.	CHECK VEHICLE SPECIFICATION

(a) Check the vehicle specification.

Result	Proceed to
for AWD	A
for 2WD	B

B

GO TO STEP 11

A

2.	CHECK REAR SPEED SENSOR RH INSTALLATION

(a) Turn the engine switch off.

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

(b) Check the rear speed sensor RH installation.

OK:

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

The installation bolt is tightened properly.

Torque

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

NG

REINSTALL OR REPLACE REAR SPEED SENSOR RH

OK

3.	CHECK REAR SPEED SENSOR RH (CHECK FOR FOREIGN MATTER)

(a) Remove the rear speed sensor RH.

Click here

(b) Check the rear speed sensor RH tip.

OK:

The rear speed sensor RH tip is free of scratches, oil, and foreign matter.

NG

CLEAN OR REPLACE REAR SPEED SENSOR RH

OK

4.	READ VALUE USING TECHSTREAM (RR WHEEL SPEED)

(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
RR Wheel Speed	Rear wheel speed sensor RH 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
RR Wheel Speed

(d) Start the engine.

(e) Perform a road test.

(f) 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.

OK

USE SIMULATION METHOD TO CHECK

NG

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.	CHECK HARNESS AND CONNECTOR (REAR SPEED SENSOR RH - 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 T2 rear speed sensor RH 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
T2-2 (RR+) - A41-20 (RR+)	Always	Below 1 Ω
T2-2 (RR+) or A41-20 (RR+) - Body ground	Always	10 kΩ or higher
T2-1 (RR-) - A41-19 (RR-)	Always	Below 1 Ω
T2-1 (RR-) or A41-19 (RR-) - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

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

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

Click here

(b) Check the rear speed sensor rotor RH.

OK:

The rear speed sensor rotor RH is free of scratches, oil, and foreign matter.

Result	Proceed to
OK	A
NG (The rear speed sensor rotor RH is damaged.)	B
NG (There is foreign matter on the rear speed sensor rotor RH.)	C

A

REPLACE REAR SPEED SENSOR RH

B

REPLACE REAR AXLE HUB AND BEARING ASSEMBLY RH

C

CLEAN REAR SPEED SENSOR ROTOR RH

8.	INSPECT REAR SKID CONTROL SENSOR WIRE RH NO. 2

(a) Turn the engine switch off.

*a Front view of rear skid control sensor wire RH No. 2 *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 z22 and T7 rear skid control sensor wire RH No. 2 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
z22-1 (RR+) - T7-2 (RR+)	Always	Below 1 Ω
z22-1 (RR+) or T7-2 (RR+) - Body ground and other terminals	Always	10 kΩ or higher
z22-3 (RR-) - T7-1 (RR-)	Always	Below 1 Ω
z22-3 (RR-) or T7-1 (RR-) - Body ground and other terminals	Always	10 kΩ or higher

NG

REPLACE REAR SKID CONTROL SENSOR WIRE RH NO. 2

OK

9.	INSPECT HARNESS AND CONNECTOR (REAR SKID CONTROL SENSOR WIRE RH 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
T7-2 (RR+) - A41-20 (RR+)	Always	Below 1 Ω
T7-2 (RR+) or A41-20 (RR+) - Body ground	Always	10 kΩ or higher
T7-1 (RR-) - A41-19 (RR-)	Always	Below 1 Ω
T7-1 (RR-) or A41-19 (RR-) - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

10.	CHECK REAR SPEED SENSOR ROTOR RH (CHECK FOR FOREIGN MATTER)

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

Click here

(b) Check the rear speed sensor rotor RH.

OK:

The rear speed sensor rotor RH is free of scratches, oil, and foreign matter.

Result	Proceed to
OK	A
NG (The rear speed sensor rotor RH is damaged.)	B
NG (There is foreign matter on the rear speed sensor rotor RH.)	C

A

REPLACE REAR SPEED SENSOR RH

B

REPLACE REAR AXLE HUB AND BEARING ASSEMBLY RH

C

CLEAN REAR SPEED SENSOR ROTOR RH

11.	CHECK REAR SPEED SENSOR RH INSTALLATION

(a) Turn the engine switch off.

*a No clearance *b Correct *c Incorrect

(b) Check the rear speed sensor RH installation.

OK:

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

HINT:

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

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

NG

REPLACE REAR AXLE HUB AND BEARING ASSEMBLY RH

OK

12.	READ VALUE USING TECHSTREAM (RR WHEEL SPEED)

(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
RR Wheel Speed	Rear wheel speed sensor RH 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
RR Wheel Speed

(d) Start the engine.

(e) Perform a road test.

(f) 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.

OK

USE SIMULATION METHOD TO CHECK

NG

13.	CHECK VEHICLE SPECIFICATION

(a) Check the vehicle specification.

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

B

GO TO STEP 16

A

14.	INSPECT REAR SKID CONTROL SENSOR WIRE RH NO. 1

(a) Turn the engine switch off.

*a Front view of rear skid control sensor wire RH No. 1 *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 j1 and Tj1 rear skid control sensor wire RH No. 1 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
j1-2 (RR+) - Tj1-2 (RR+)	Always	Below 1 Ω
j1-2 (RR+) or Tj1-2 (RR+) - Body ground and other terminals	Always	10 kΩ or higher
j1-1 (RR-) - Tj1-1 (RR-)	Always	Below 1 Ω
j1-1 (RR-) or Tj1-1 (RR-) - Body ground and other terminals	Always	10 kΩ or higher

NG

REPLACE REAR SKID CONTROL SENSOR WIRE RH NO. 1

OK

15.	CHECK HARNESS AND CONNECTOR (REAR SKID CONTROL SENSOR WIRE RH 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
Tj1-2 (RR+) - A41-20 (RR+)	Always	Below 1 Ω
Tj1-2 (RR+) or A41-20 (RR+) - Body ground	Always	10 kΩ or higher
Tj1-1 (RR-) - A41-19 (RR-)	Always	Below 1 Ω
Tj1-1 (RR-) or A41-19 (RR-) - Body ground	Always	10 kΩ or higher

HINT:

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

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

OK

REPLACE REAR AXLE HUB AND BEARING ASSEMBLY RH

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

(a) Turn the engine switch off.

*a Front view of rear skid control sensor wire RH No. 1 *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 j1 and j5 rear skid control sensor wire RH No. 1 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
j1-2 (RR+) - j5-1 (RR+)	Always	Below 1 Ω
j1-2 (RR+) or j5-1 (RR+) - Body ground and other terminals	Always	10 kΩ or higher
j1-1 (RR-) - j5-3 (RR-)	Always	Below 1 Ω
j1-1 (RR-) or j5-3 (RR-) - Body ground and other terminals	Always	10 kΩ or higher

NG

REPLACE REAR SKID CONTROL SENSOR WIRE RH NO. 1

OK

17.	INSPECT REAR SKID CONTROL SENSOR WIRE RH 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 RH No. 2 *b (to Sensor Side Connector) *c (to Vehicle Side Connector)

(b) Disconnect the T7 rear skid control sensor wire RH 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
j5-1 (RR+) - T7-2 (RR+)	Always	Below 1 Ω
j5-1 (RR+) or T7-2 (RR+) - Body ground and other terminals	Always	10 kΩ or higher
j5-3 (RR-) - T7-1 (RR-)	Always	Below 1 Ω
j5-3 (RR-) or T7-1 (RR-) - Body ground and other terminals	Always	10 kΩ or higher

NG

REPLACE REAR SKID CONTROL SENSOR WIRE RH NO. 2

OK

18.	CHECK HARNESS AND CONNECTOR (REAR SKID CONTROL SENSOR WIRE RH 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
T7-2 (RR+) - A41-20 (RR+)	Always	Below 1 Ω
T7-2 (RR+) or A41-20 (RR+) - Body ground	Always	10 kΩ or higher
T7-1 (RR-) - A41-19 (RR-)	Always	Below 1 Ω
T7-1 (RR-) or A41-19 (RR-) - Body ground	Always	10 kΩ or higher

HINT:

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

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

OK

REPLACE REAR AXLE HUB AND BEARING ASSEMBLY RH

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR