DTC C050C-23: Left Rear Wheel Speed Sensor Signal Stuck Low [11/2021 - 10/2023]: Procedure

1. Check the rear speed sensor LH installation.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Correct
   *b	Incorrect

   OK

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

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REINSTALL OR REPLACE REAR SPEED SENSOR LH. Refer to  REMOVAL [10/2017 - ] 

Result: 

OK 

See step  2

1. Remove the rear speed sensor LH.

   Refer to REMOVAL [10/2017 - ]

2. Check the rear speed sensor tip LH.

   OK

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

   NOTE:

   • If there is oil or foreign matter on the rear speed sensor LH, clean the rear speed sensor LH.
   • If the rear speed sensor LH is damaged, replace the rear speed sensor LH with a new one.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CLEAN OR REPLACE REAR SPEED SENSOR LH 

Result: 

OK 

See step  3

1. Perform a road test.
2. Check the rear speed sensor LH output value.

   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 mph) Max.: 6553.5 km/h (4072 mph)	Vehicle stopped: 0.0 km/h (0 mph)	When driving at constant speed: No large fluctuations

   Chassis > Brake/EPB > Data List 

   Tester Display
   RL Wheel Speed

   OK

   The output value changes in accordance with the vehicle speed.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2021 - 10/2022]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - 10/2023] 

Result: 

NG 

See step  4

1. Turn the ignition switch off.
2. Make sure that there is no looseness at the locking part and the connecting part of the connectors.

   OK

   The connector is securely connected.

3. Disconnect the L178 and LL4 skid control sensor wire LH connector.
4. Check both the connector case and the terminals for deformation and corrosion.

   OK

   No deformation or corrosion.

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   L178-2 (RL+) - LL4-3	Always	Below 1 Ω
   L178-2 (RL+) or LL4-3 - Body ground and other terminals	Always	10 kΩ or higher
   L178-1 (RL-) - LL4-4	Always	Below 1 Ω
   L178-1 (RL-) or LL4-4 - Body ground and other terminals	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE SKID CONTROL SENSOR WIRE LH 

Result: 

OK 

See step  5

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

   OK

   The connector is securely connected.

2. Disconnect the A102 No. 2 skid control ECU (brake actuator assembly) connector.
3. Check both the connector case and the terminals for deformation and corrosion.

   OK

   No deformation or corrosion.

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   LL4-3 - A102-5 (RL+)	Always	Below 1 Ω
   LL4-3 or A102-5 (RL+) - Body ground	Always	10 kΩ or higher
   LL4-4 - A102-4 (RL-)	Always	Below 1 Ω
   LL4-4 or A102-4 (RL-) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  6

1. Remove the component with the rear speed sensor rotor LH.

   Refer to REMOVAL [11/2021 - 10/2022] , or refer to REMOVAL [10/2022 - 10/2023]

2. Check the rear speed sensor rotor LH.

   OK

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

   NOTE:

   • If there is oil or foreign matter on the rear speed sensor rotor LH, clean the rear speed sensor rotor LH.
   • Do not use parts cleaner when cleaning the rear speed sensor rotor LH.
   • If the rear speed sensor rotor LH is damaged, replace the rear speed sensor rotor LH with a new one.

   HINT: 

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

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

   Result

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

Result: 

A 

REPLACE REAR SPEED SENSOR LH. Refer to  REMOVAL [10/2017 - ] 

Result: 

B 

REPLACE REAR AXLE HUB AND BEARING ASSEMBLY LH. Refer to  REMOVAL [11/2021 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023] 

Result: 

C 

CLEAN REAR SPEED SENSOR ROTOR LH