BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): C121F62; Electronic Brake Booster Control Module "A" Signal Compare Failure; 2023 - 2025 MY Corolla Corolla HV [09/2022

Last Modified: 05-13-2024	6.11:8.1.0	Doc ID: RM1000000025DU4
Model Year Start: 2023	Model: Corolla	Prod Date Range: [09/2022 - ]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): C121F62; Electronic Brake Booster Control Module "A" Signal Compare Failure; 2023 - 2025 MY Corolla Corolla HV [09/2022 - ]

DTC

C121F62

Electronic Brake Booster Control Module "A" Signal Compare Failure

DESCRIPTION

When the self-check function of the electric brake booster (brake booster with master cylinder assembly) detects an internal circuit malfunction, this DTC is stored.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	DTC Output from	Note
C121F62	Electronic Brake Booster Control Module "A" Signal Compare Failure	Electric brake booster (brake booster with master cylinder assembly) internal malfunction detected.	Electric brake booster (brake booster with master cylinder assembly)	Comes on	Brake Booster	SAE Code: C121F (Case 1) Output ECU: Electric brake booster (brake booster with master cylinder assembly)

MONITOR DESCRIPTION

When the electronically controlled brake system is starting and the non-volatile memory in the electric brake booster (brake booster with master cylinder assembly) is invalid or cannot be read, the electric brake booster (brake booster with master cylinder assembly) illuminates the MIL and stores this DTC.

MONITOR STRATEGY

Related DTCs	C121F (Case 1): EEPROM read error
Required Sensors/Components(Main)	Electric brake booster (brake booster with master cylinder assembly)
Required Sensors/Components(Related)	Electric brake booster (brake booster with master cylinder assembly)
Frequency of Operation	During initial checking
Duration	-
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 Booster / Utility / All Readiness.
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 BOOSTER WITH MASTER CYLINDER ASSEMBLY

Click here

END