BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): C050C12; Left Rear Wheel Speed Sensor Circuit Short to Battery; 2023 - 2025 MY Corolla Corolla HV [09/2022

Last Modified: 07-31-2024	6.11:8.1.0	Doc ID: RM1000000025DTA
Model Year Start: 2023	Model: Corolla	Prod Date Range: [09/2022 - ]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): C050C12; Left Rear Wheel Speed Sensor Circuit Short to Battery; 2023 - 2025 MY Corolla Corolla HV [09/2022 - ]

DTC

C050C12

Left Rear Wheel Speed Sensor Circuit Short to Battery

DESCRIPTION

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

The speed sensor detects the magnetic fields of the speed sensor rotor as it rotates and outputs a pulse signal.

The frequency of the pulse varies in accordance with the rotational speed of the speed sensor rotor and the system uses this to determine the wheel speed.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	DTC Output from	Note
C050C12	Left Rear Wheel Speed Sensor Circuit Short to Battery	A short to +B in the speed sensor signal circuit is detected for 0.12 seconds or more.	Rear speed sensor LH1 Rear speed sensor LH (rear axle hub and bearing assembly LH)2 Wire harness or connector Skid control sensor wire LH (No. 2 parking brake wire assembly) Skid control ECU (brake actuator assembly)	Comes on	Brake/EPB	SAE Code: C050F (Case 1) Output ECU: Skid control ECU (brake actuator assembly)

*1: for AWD
*2: for 2WD

MONITOR DESCRIPTION

The skid control ECU (brake actuator assembly) has a speed sensor circuit self-diagnosis function.

When it is detected by the self-diagnosis function that is performed during system startup that the current of the speed sensor circuit exceeds a certain value, the skid control ECU (brake actuator assembly) illuminates the MIL and stores this DTC.

MONITOR STRATEGY

Related DTCs	C050F: Wheel speed sensor line monitoring for RL (signal line short to BATT)
Required Sensors/Components(Main)	Skid control ECU (brake actuator assembly)
Required Sensors/Components(Related)	Skid control ECU (brake actuator assembly)
Frequency of Operation	Continuous
Duration	0.12 seconds
MIL Operation	2 driving cycles
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever the following DTCs are not stored	TMC's intellectual property
Other conditions belong to TMC's intellectual property	-

TYPICAL MALFUNCTION THRESHOLDS

TMC's intellectual property

COMPONENT OPERATING RANGE

TMC's intellectual property

CONFIRMATION DRIVING PATTERN

NOTICE:

When performing the normal judgment procedure, make sure that the driver door is closed and is not opened at any time during the procedure.

HINT:

After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.

Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off.
Turn the ignition switch to ON (READY) and turn the GTS on.
Wait for 1 second or more. [*]
HINT:

[*]: Normal judgment procedure.

The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
Enter the following menus: Chassis / Brake/EPB* / Utility / All Readiness.
*: Electric Parking Brake System
Check the DTC judgment result.
HINT:
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows INCOMPLETE, perform driving pattern again.

WIRING DIAGRAM

for 2WD

for AWD

PROCEDURE

1.	CHECK VEHICLE

(a) Check the vehicle specification.

Result	Proceed to
for 2WD	A
for AWD	B

GO TO STEP 6

2.	CHECK HARNESS AND CONNECTOR (SENSOR GROUND CIRCUIT)

(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 skid control sensor wire LH (No. 2 parking brake wire assembly) (to Rear Speed Sensor LH (Rear Axle Hub and Bearing Assembly LH))

(b) Disconnect the n2 rear speed sensor LH (rear axle hub and bearing assembly LH) connector.

OK:

No deformation or corrosion.

(d) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
n2-2 (LA+) - n2-1 (LA-)	Ignition switch ON	11 to 14 V

REPLACE REAR AXLE HUB AND BEARING ASSEMBLY LH

3.	CHECK HARNESS AND CONNECTOR (SENSOR GROUND CIRCUIT)

(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 wire harness connector (to Skid Control Sensor Wire LH (No. 2 Parking Brake Wire Assembly))

(b) Disconnect the nO2 skid control sensor wire LH (No. 2 parking brake wire assembly) connector.

OK:

No deformation or corrosion.

(d) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
nO2-1 (RL+) - nO2-2 (RL-)	Ignition switch ON	11 to 14 V

REPLACE NO. 2 PARKING BRAKE WIRE ASSEMBLY

4.	CHECK HARNESS AND CONNECTOR (NO. 2 PARKING BRAKE WIRE ASSEMBLY - 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.

*a	Front view of wire harness connector (to Skid Control Sensor Wire LH (No. 2 Parking Brake Wire Assembly))

(b) Disconnect the A51 skid control ECU (brake actuator assembly) connector.

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

OK:

No deformation or corrosion.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
nO2-2 (RL-) - Body ground	Always	Below 1.5 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	CHECK HARNESS AND CONNECTOR (NO. 2 PARKING BRAKE WIRE ASSEMBLY - 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 A51 skid control ECU (brake actuator assembly) 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
nO2-1 (RL+) or A51-39 (RL+) - nO2-2 (RL-) or A51-23 (RL-)	Always	10 kΩ or higher

REPLACE BRAKE ACTUATOR ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.	CHECK HARNESS AND CONNECTOR (SENSOR GROUND CIRCUIT)

(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 skid control sensor wire LH (No. 2 parking brake wire assembly) (to Rear Speed Sensor LH)

(b) Disconnect the n2 rear speed sensor LH connector.

OK:

No deformation or corrosion.

(d) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
n2-2 (LA+) - n2-1 (LA-)	Ignition switch ON	11 to 14 V

REPLACE REAR SPEED SENSOR LH

GO TO STEP 3