BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): C12A512,...,C12B049; Left Front Wheel ABS Hold Solenoid Control Circuit Short to Battery; 2023 - 2025 MY Corolla Corolla HV [09/2022

Last Modified: 05-13-2024	6.11:8.1.0	Doc ID: RM1000000025DUB
Model Year Start: 2023	Model: Corolla	Prod Date Range: [09/2022 - ]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): C12A512,...,C12B049; Left Front Wheel ABS Hold Solenoid Control Circuit Short to Battery; 2023 - 2025 MY Corolla Corolla HV [09/2022 - ]

DTC

C12A512

Left Front Wheel ABS Hold Solenoid Control Circuit Short to Battery

DTC

C12A514

Left Front Wheel ABS Hold Solenoid Control Circuit Short to Ground or Open

DTC

C12A51C

Left Front Wheel ABS Hold Solenoid Control Circuit Voltage Out of Range

DTC

C12A51E

Left Front Wheel ABS Hold Solenoid Control Circuit Resistance Out of Range

DTC

C12A549

Left Front Wheel ABS Hold Solenoid Control Internal Electronic Failure

DTC

C12B012

Left Front Wheel ABS Release Solenoid Control Circuit Short to Battery

DTC

C12B014

Left Front Wheel ABS Release Solenoid Control Circuit Short to Ground or Open

DTC

C12B01C

Left Front Wheel ABS Release Solenoid Control Circuit Voltage Out of Range

DTC

C12B01E

Left Front Wheel ABS Release Solenoid Control Circuit Resistance Out of Range

DTC

C12B049

Left Front Wheel ABS Release Solenoid Control Internal Electronic Failure

DESCRIPTION

The ABS solenoid relay and solenoid valves are built into the brake actuator assembly.

The front solenoid valve LH controls the brake fluid pressure of the front wheel cylinder LH of the vehicle.

When this DTC is stored, the fail-safe function operates and the ABS solenoid relay is turned off to prevent the solenoid valves from operating.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	DTC Output from	Note
C12A512	Left Front Wheel ABS Hold Solenoid Control Circuit Short to Battery	A short to +B in the solenoid circuit is detected during the self-test.	Skid control ECU (brake actuator assembly)	Comes on	Brake/EPB	SAE Code: C12A8 Output ECU: Skid control ECU (brake actuator assembly)
C12A514	Left Front Wheel ABS Hold Solenoid Control Circuit Short to Ground or Open	An open or short in the solenoid circuit is detected during the self-test.	Skid control ECU (brake actuator assembly)	Comes on	Brake/EPB	SAE Code: C12A7 Output ECU: Skid control ECU (brake actuator assembly)
C12A51C	Left Front Wheel ABS Hold Solenoid Control Circuit Voltage Out of Range	A current leak in the solenoid circuit is detected during the self-test. The solenoid operation request signal and solenoid operation feedback signal do not match for a certain period of time.	Skid control ECU (brake actuator assembly)	Comes on	Brake/EPB	SAE Code: C12A6 (Case 1 to 4) Output ECU: Skid control ECU (brake actuator assembly)
C12A51E	Left Front Wheel ABS Hold Solenoid Control Circuit Resistance Out of Range	An abnormal resistance in the solenoid circuit is detected during the self-test.	Skid control ECU (brake actuator assembly)	Comes on	Brake/EPB	SAE Code: C12A6 (Case 5) Output ECU: Skid control ECU (brake actuator assembly)
C12A549	Left Front Wheel ABS Hold Solenoid Control Internal Electronic Failure	An internal malfunction in the solenoid circuit is detected during the self-test.	Skid control ECU (brake actuator assembly)	Comes on	Brake/EPB	SAE Code: C12A5 Output ECU: Skid control ECU (brake actuator assembly)
C12B012	Left Front Wheel ABS Release Solenoid Control Circuit Short to Battery	A short to +B in the solenoid circuit is detected during the self-test.	Skid control ECU (brake actuator assembly)	Comes on	Brake/EPB	SAE Code: C12B3 Output ECU: Skid control ECU (brake actuator assembly)
C12B014	Left Front Wheel ABS Release Solenoid Control Circuit Short to Ground or Open	An open or short in the solenoid circuit is detected during the self-test.	Skid control ECU (brake actuator assembly)	Comes on	Brake/EPB	SAE Code: C12B2 Output ECU: Skid control ECU (brake actuator assembly)
C12B01C	Left Front Wheel ABS Release Solenoid Control Circuit Voltage Out of Range	A current leak in the solenoid circuit is detected during the self-test. The solenoid operation request signal and solenoid operation feedback signal do not match for a certain period of time.	Skid control ECU (brake actuator assembly)	Comes on	Brake/EPB	SAE Code: C12B1 (Case 1 to 4) Output ECU: Skid control ECU (brake actuator assembly)
C12B01E	Left Front Wheel ABS Release Solenoid Control Circuit Resistance Out of Range	An abnormal resistance in the solenoid circuit is detected during the self-test.	Skid control ECU (brake actuator assembly)	Comes on	Brake/EPB	SAE Code: C12B1 (Case 5) Output ECU: Skid control ECU (brake actuator assembly)
C12B049	Left Front Wheel ABS Release Solenoid Control Internal Electronic Failure	An internal malfunction in the solenoid circuit is detected during the self-test.	Skid control ECU (brake actuator assembly)	Comes on	Brake/EPB	SAE Code: C12B0 Output ECU: Skid control ECU (brake actuator assembly)

MONITOR DESCRIPTION

C12A5 and C12B0:

When the ABS solenoid is not operating and the self-diagnosis function detects an internal malfunction in the ABS solenoid circuit, the skid control ECU (brake actuator assembly) illuminates the MIL and stores this DTC.

C12A6 (Case 1) and C12B1 (Case 1):

If the self-diagnosis function detects that the feedback value from the ABS solenoid drive circuit does not match the operation request value, the skid control ECU (brake actuator assembly) illuminates the MIL and stores this DTC.

C12A6 (Case 2) and C12B1 (Case 2):

When the downstream voltage of the ABS solenoid or the current flowing in the ABS solenoid is less than a certain value, the skid control ECU (brake actuator assembly) illuminates the MIL and stores this DTC.

C12A6 (Case 3) and C12B1 (Case 3):

When the ABS solenoid is not operating and the current flowing in the ABS solenoid exceeds a certain value (current leak is detected), the skid control ECU (brake actuator assembly) illuminates the MIL and stores this DTC.

C12A6 (Case 4) and C12B1 (Case 4):

If the current flowing in the ABS solenoid circuit, circuit temperature, or voltage drop within the circuit is a certain value or more, the skid control ECU (brake actuator assembly) judges that there is an ABS solenoid overcurrent malfunction and illuminates the MIL and stores this DTC.

C12A6 (Case 5) and C12B1 (Case 5):

If the ABS solenoid is not operating and the resistance value of the ABS solenoid is outside of a certain range, the skid control ECU (brake actuator assembly) illuminates the MIL and stores this DTC.

C12A7 and C12B2:

If the current, voltage or temperature of the ABS solenoid circuit is less than or exceeds a certain value, or the operation request value and feedback value deviate by a certain value or more, the skid control ECU (brake actuator assembly) illuminates the MIL and stores this DTC.

C12A8 and C12B3:

If the self-diagnosis function detects a short to +B in the ABS solenoid circuit, the skid control ECU (brake actuator assembly) illuminates the MIL and stores this DTC.

MONITOR STRATEGY

Related DTCs	C12A5: Cyclic valve test for SFLH (built in self-test) C12A6 (Case 1): Valve feedback monitoring for SFLH (PWM check) C12A6 (Case 2): Valve feedback monitoring for SFLH (valve-coil path interruption) C12A6 (Case 3): Cyclic valve test (current leakage test) for SFLH C12A6 (Case 4): Valve feedback monitoring for SFLH (general application specific integrated circuit valve driver failure) C12A6 (Case 5): Cyclic valve test (valve resistance check) for SFLH C12A7: Cyclic valve test (silent valve driver test) for SFLH C12A8: Cyclic valve test (valve actuation register test) for SFLH C12B0: Cyclic valve test for SFLR (built in self-test) C12B1 (Case 1): Valve feedback monitoring for SFLR (PWM check) C12B1 (Case 2): Valve feedback monitoring for SFLR (valve-coil path interruption) C12B1 (Case 3): Cyclic valve test (current leakage test) for SFLR C12B1 (Case 4): Valve feedback monitoring for SFLR (general application specific integrated circuit valve driver failure) C12B1 (Case 5): Cyclic valve test (valve resistance check) for SFLR C12B2: Cyclic valve test (silent valve driver test) for SFLR C12B3: Cyclic valve test (valve actuation register test) for SFLR
Required Sensors/Components(Main)	Skid control ECU (brake actuator assembly)
Required Sensors/Components(Related)	Skid control ECU (brake actuator assembly)
Frequency of Operation	During initial checking
Duration	-: C12A5, C12A6 (Case 3 and 5), C12A7, C12A8, C12B1 (Case 3 and 5), C12B2 and C12B3 0.03 seconds: C12A6 (Case 1, 2 and 4), C12B1 (Case 1, 2 and 4) 20 seconds: C12B0
MIL Operation	Immediately
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.

PROCEDURE

1.	REPLACE BRAKE ACTUATOR ASSEMBLY

Click here

END