Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001G7B7
Model Year Start: 2020 Model: Corolla Prod Date Range: [01/2019 - 04/2020]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): C1241; Low or High Power Supply Voltage; 2020 MY Corolla Corolla HV [01/2019 - 04/2020]

DTC

C1241

Low or High Power Supply Voltage

DESCRIPTION

If a malfunction is detected in the power supply circuit, the skid control ECU (brake booster with master cylinder assembly) power source voltage drops, or there is insufficient voltage to operate the main relay, the skid control ECU (brake booster with master cylinder assembly) will store these DTCs.

If the auxiliary battery voltage is temporarily low, these DTCs may be stored.

HINT:

DTC C1256 (Accumulator Low Pressure) may also be memorized if there is a drop in power source voltage.

DTC No.

Detection Item

INF Code

DTC Detection Condition

Trouble Area

MIL

Note

C1241

Low or High Power Supply Voltage

101

102

103

551

552

554
  • INF Code: 101
    • Either of the following is detected when the BS terminal voltage is 9.1 V or less:
      1. The brake is not applied for 3 seconds or more.
      2. The brake is applied for 0.05 seconds or more.
  • INF Code: 102
    • Any of the following is detected when the ECU internal voltage is 6.92 V or less:
      1. The relay output voltage is less than 3.5 V for 0.05 seconds or more, when the main relay operation command is on.
      2. The stroke sensor value invalid for 0.2 seconds or more.
      3. The reaction force pressure sensor value invalid for 0.2 seconds or more.
      4. The servo pressure sensor power source voltage is 6.29 V or less, or 7.64 V or more for 0.06 seconds or more.
      5. The servo pressure sensor value invalid for 0.2 seconds or more.
      6. The reaction force pressure sensor power source voltage is 6.29 V or less, or 7.64 V or more for 0.06 seconds or more.
  • INF Code: 103
    • When the ECU internal voltage is 8.3 V or less, the accumulator pressure sensor value is invalid for 0.8 seconds or more.
    • Either of the following is detected when the ECU internal voltage is 6.9 V or less:
      1. When the accumulator pressure sensor value is 15 MPa (153 kgf/cm2, 2176 psi) or less, the pump motor does not operate for 1 second or more.
      2. Both the motor relay 1 and 2 cannot be operated for 0.2 seconds or more.
  • INF Code: 551
    • Either of the following is detected when the BS voltage of the ABS unit is 9.1 V or less:
      1. The brake is not applied for 3 seconds or more.
      2. The brake is applied for 0.05 seconds or more.
  • INF Code: 552
    • The speed sensor power voltage is invalid for 60 seconds or more.
  • INF Code: 554
    • The voltage of IG1 or IG2 is 9.5 V or less for 10 seconds or more.
  • Improperly connected connector, deformation or corrosion of terminals
  • Auxiliary battery
  • Hybrid control system (Charging circuit)
  • Skid control ECU (brake booster with master cylinder assembly)
  • Wire harness or connector

Comes on
  • INF Code 101: SAE Code C14DE
  • INF Code 102: SAE Code C1241 (Case 1 to 7)
  • INF Code 103: SAE Code C1241 (Case 8 to 10)
  • INF Code 551: SAE Code C14DB (Case 1 and 2)
  • INF Code 552: SAE Code C1241 (Case 12)
  • INF Code 554: SAE Code C1241 (Case 11)
  • Electronically controlled brake system DTC

MONITOR DESCRIPTION

  • When the voltage at VM1, VM2, IG1, IG2 or BS drops due to a malfunction in the auxiliary battery and hybrid control system (charging circuit), the skid control ECU (brake booster with master cylinder assembly) judges that there is a drop in the power supply and illuminates the MIL and stores a DTC.

MONITOR STRATEGY

Related DTCs

C1241: Brake system voltage circuit low

C14DB: ABS solenoid power supply voltage circuit low

C14DE: Main relay voltage circuit low

Required Sensors/Components(Main)

Brake pedal stroke sensor assembly

Skid control ECU (brake booster with master cylinder assembly)

Brake booster pump assembly

Brake actuator assembly

Brake actuator (brake booster with master cylinder assembly)

Required Sensors/Components(Related)

Speed sensor

Skid control ECU (brake booster with master cylinder assembly)

Frequency of Operation

Continuous

Duration

-: C1241 (Case 6), C1241 (Case 7) and C14DE (Case 1)

Within 1 second: C1241 (Case 1), C1241 (Case 2), C1241 (Case 3), C1241 (Case 4), C1241 (Case 5), C1241 (Case 8), C1241 (Case 9), C1241 (Case 10), C14DB (Case 2) and C14DE (Case 3)

3 seconds: C14DB (Case 1) and C14DE (Case 2)

10 seconds: C1241 (Case 11)

60 seconds: C1241 (Case 12)

MIL Operation

Immediately

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

C1241 (Case 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10)

Monitor runs whenever the following DTCs are not stored

None

Vehicle electric power supply

Stable state

C1241 (Case 11)

Monitor runs whenever the following DTCs are not stored

None

Both of the following conditions are met

-

IG1

On

Vehicle speed

Higher than 3 km/h (2 mph)

C1241 (Case 12)

Monitor runs whenever the following DTCs are not stored

None

IG1

On

C14DB

Monitor runs whenever the following DTCs are not stored

C146E (ABS solenoid power supply relay circuit low)

All of the following conditions are met

-

Vehicle electric power supply

Stable state

Command to ABS solenoid power supply relay

On

ABS solenoid power supply relay

On

ABS solenoid power supply relay fail (C146E)

Not detected

C14DE

Monitor runs whenever the following DTCs are not stored

C12FA (Main relay circuit low)

All of the following conditions are met

-

Vehicle electric power supply

Stable state

Command to main relay

On

Main relay

On

Main relay fail (C12FA)

Not detected

TYPICAL MALFUNCTION THRESHOLDS

C1241 (Case 1)

Both of the following conditions are met

-

Brake pedal stroke sensor assembly data

Invalid

Brake system voltage 1 (VM1)

6.92 V or less

C1241 (Case 2)

Both of the following conditions are met

-

Reaction force pressure sensor data

Invalid

Brake system voltage 1 (VM1)

8.27 V or less

C1241 (Case 3)

Both of the following conditions are met

-

Reaction force pressure sensor power supply

Less than 6.29 V, or higher than 7.64 V

Brake system voltage 1 (VM1)

8.27 V or less

C1241 (Case 4)

Both of the following conditions are met

-

Servo pressure sensor data

Invalid

Brake system voltage 1 (VM1)

8.27 V or less

C1241 (Case 5)

Both of the following conditions are met

-

Servo pressure sensor power supply

Less than 6.29 V, or higher than 7.64 V

Brake system voltage 1 (VM1)

8.27 V or less

C1241 (Case 6)

All of the following conditions are met

A, B and C

A. Power switch

Off

B. Either of the following conditions is met

-

Main relay

Off and there is on experience

ABS solenoid power supply relay

Off and there is on experience

C. Brake system voltage 1 (VM1)

6.92 V or less

C1241 (Case 7)

All of the following conditions are met

A, B, C and D

A. Power switch

On (READY)

B. Either of the following conditions is met

-

Main relay

Off and there is on experience

ABS solenoid power supply relay

Off and there is on experience

C. Brake system voltage 1 (VM1)

6.92 V or less

D. IG1 voltage

9.54 V or less

C1241 (Case 8)

Both of the following conditions are met

-

Accumulator pressure data

Invalid

Brake system voltage 2 (VM2)

8.27 V or less

C1241 (Case 9)

All of the following conditions are met

-

Serial communication with low side IC

Valid

Pump motor operating from IC

Enable

Accumulator pressure

Less than 15.3 MPa (156 kgf/cm2, 2219 psi) (Pump motor on pressure)

Brake system voltage 2 (VM2)

6.92 V or less

C1241 (Case 10)

All of the following conditions are met

-

Pump motor

Operating from IC

Pump motor voltage

Less than 6 V

Brake system voltage 2 (VM2)

6.92 V or less

C1241 (Case 11)

One of the following conditions is met

A, B or C

A. IG1 voltage

9.54 V or less

B. Both of the following conditions are met

-

IG2

On

IG2 voltage

9.54 V or less

C. Brake system voltage 1 (VM1)

7.54 V or less

C1241 (Case 12)

Both of the following conditions are met

-

Brake system voltage 1 (VM1)

7.54 V or less

Speed sensor power supply voltage (all of wheels)

Less than 6.1 V

C14DB (Case 1)

Both of the following conditions are met

-

Power supply for ABS solenoid

9.13 V or less

Brake control

Off

C14DB (Case 2)

Both of the following conditions are met

-

Power supply for ABS solenoid

9.13 V or less

Brake control

On

C14DE (Case 1)

All of the following conditions are met

A, B and C

A. Power supply for linear solenoid

9.13 V or less

B. Either of the following conditions is met

-

Linear solenoid (SLA) current drop signal

On

Linear solenoid (SLR) current drop signal

On

C. Brake control

On

C14DE (Case 2)

Both of the following conditions are met

-

Power supply for linear solenoid

9.13 V or less

Brake control

Off

C14DE (Case 3)

Both of the following conditions are met

-

Power supply for linear solenoid

9.13 V or less

Brake control

On

COMPONENT OPERATING RANGE

C1241 (Case 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10)

Both of the following conditions are met

-

Vehicle electric power supply

Stable state

Power supply common pass condition

Met

C1241 (Case 11)

All of the following conditions are met

-

Control valve solenoid

non-drive

IG1 voltage

Higher than 9.54 V

IG2 voltage

Higher than 9.54 V

Brake system voltage 1 (VM1)

Higher than 7.54 V

C1241 (Case 12)

Both of the following conditions are met

-

IG1

On

Brake system voltage 1 (VM1)

Higher than 7.54 V

C14DB

All of the following conditions are met

-

Vehicle electric power supply

Stable state

Command to ABS solenoid power supply relay

On

ABS solenoid power supply relay

On

ABS solenoid power supply relay fail (C146E)

Not detected

Power supply common pass condition

Met

C14DE

All of the following conditions are met

-

Vehicle electric power supply

Stable state

Command to main relay

On

Main relay

On

Main relay fail (C12FA)

Not detected

Power supply common pass condition

Met

CONFIRMATION DRIVING PATTERN

  1. Connect the Techstream to the DLC3.
  2. Turn the power switch on (IG).
  3. Turn the Techstream on.
  4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  5. Turn the power switch off.
  6. Turn the power switch on (READY).
  7. Turn the Techstream on.
  8. Drive the vehicle at 10 km/h (6 mph) or more for 60 seconds or more.
  9. Enter the following menus: Chassis / ABS/VSC/TRAC / Trouble Codes.
  10. Read the DTCs.

    HINT:

    • If a DTC is output, the system is malfunctioning.
    • If a DTC is not output, perform the following procedure.
  11. If the DTCs are not output, perform a universal trip and check for permanent DTCs.

    Click here 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): DTC CHECK / CLEAR

    HINT:

    • If a permanent DTC is output, the system is malfunctioning.
    • If no permanent DTCs are output, the system is normal.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • After replacing the skid control ECU (brake booster with master cylinder assembly), perform linear solenoid valve offset learning, ABS holding solenoid valve learning, yaw rate and acceleration sensor zero point calibration and system information memorization after performing "Reset Memory".

    Click here 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): INITIALIZATION

  • Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.

CHECK DTC

(a) Check the DTCs that are output.

Click here 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): DTC CHECK / CLEAR

Chassis > ABS/VSC/TRAC > Trouble Codes

Result

Proceed to

Only DTC C1241 is output.

A

DTC C1311 is output with DTC C1241.

B
B

GO TO DTC (C1311)

A

2.

CHECK AUXILIARY BATTERY

(a) Select the Data List on the Techstream.

Click here 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): DATA LIST / ACTIVE TEST

Powertrain > Hybrid Control > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

BATT Voltage

Auxiliary battery voltage

(Battery voltage sensor power source voltage)

Min.: 0.00 V, Max.: 79.99 V

11.00 to 15.00 V

BATT terminal

Powertrain > Hybrid Control > Data List

Tester Display

BATT Voltage

(b) Check the Techstream display condition of the auxiliary battery voltage.

Result

Proceed to

The auxiliary battery voltage is 11 to 15 V.

A

The auxiliary battery voltage is below 11 V.

B
B

CHARGE OR REPLACE AUXILIARY BATTERY
A

3.

CHECK FREEZE FRAME DATA

(a) Check the INF code from the Freeze Frame Data stored when DTC (C1241) was stored.

Click here 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): FREEZE FRAME DATA

Chassis > ABS/VSC/TRAC > Trouble Codes

Result

Proceed to

INF code 101 or 551 is output.

A

INF code 102 or 552 is output.

B

INF code 103 is output.

C

INF code 554 is output.

D
B

GO TO STEP 5

C

GO TO STEP 6

D

GO TO STEP 7

A

4.

CHECK HARNESS AND CONNECTOR (BS TERMINAL)

(a) Turn the power switch off.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

(c) Disconnect the A48 skid control ECU (brake booster with master cylinder 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

A48-52 (BS) - Body ground

Always

11 to 14 V

Result

Proceed to

11 to 14 V.

A

Below 11 V.

B
A

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

B

REPAIR OR REPLACE HARNESS OR CONNECTOR (BS CIRCUIT)

5.

CHECK HARNESS AND CONNECTOR (IG1, +BI1 AND BS TERMINAL)

(a) Turn the power switch off.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

(c) Disconnect the A48 skid control ECU (brake booster with master cylinder assembly) connector.

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

OK:

No deformation or corrosion.

(e) Turn the power switch on (IG).

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A48-15 (+BI1) - Body ground

Power switch on (IG)

11 to 14 V

A48-52 (BS) - Body ground

Power switch on (IG)

11 to 14 V

A48-23 (IG1) - Body ground

Power switch on (IG)

11 to 14 V

Result

Proceed to

11 to 14 V.

A

Below 11 V.

B
A

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

B

REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1, +BI1 AND/OR BS CIRCUIT)

6.

CHECK HARNESS AND CONNECTOR (IG1, IG2, +BI1, +BI2 AND BS TERMINAL)

(a) Turn the power switch off.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

(c) Disconnect the A48 skid control ECU (brake booster with master cylinder assembly) connector.

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

OK:

No deformation or corrosion.

(e) Turn the power switch on (IG).

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A48-15 (+BI1) - Body ground

Power switch on (IG)

11 to 14 V

A48-5 (+BI2) - Body ground

Power switch on (IG)

11 to 14 V

A48-52 (BS) - Body ground

Power switch on (IG)

11 to 14 V

A48-23 (IG1) - Body ground

Power switch on (IG)

11 to 14 V

A48-9 (IG2) - Body ground

Power switch on (IG)

11 to 14 V

Result

Proceed to

11 to 14 V.

A

Below 11 V.

B
A

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

B

REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1, IG2, +BI1, +BI2 AND/OR BS CIRCUIT)

7.

CHECK HARNESS AND CONNECTOR (IG1 AND IG2 TERMINAL)

(a) Turn the power switch off.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

(c) Disconnect the A48 skid control ECU (brake booster with master cylinder assembly) connector.

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

OK:

No deformation or corrosion.

(e) Turn the power switch on (IG).

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A48-23 (IG1) - Body ground

Power switch on (IG)

11 to 14 V

A48-9 (IG2) - Body ground

Power switch on (IG)

11 to 14 V

Result

Proceed to

11 to 14 V.

A

Below 11 V.

B
A

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

B

REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 AND/OR IG2 CIRCUIT)