Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001ANKY
Model Year Start: 2019 Model: Avalon HV Prod Date Range: [04/2018 -           ]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): C1427; Malfunction in Motor; 2019 - 2022 MY Avalon HV [04/2018 -        ]

DTC

C1427

Malfunction in Motor

DESCRIPTION

When the power switch is on (READY), the stop light switch assembly off and the vehicle speed is 20 km/h (12 mph) or more, the skid control ECU (brake booster with master cylinder assembly) performs a self-diagnosis of the ABS motor relay circuit during the initial check of the actuator.

DTC No.

Detection Item

INF Code

DTC Detection Condition

Trouble Area

MIL

Note

C1427

Malfunction in Motor

1159

The pump motor built into the brake actuator assembly is not operating correctly.
  • Wire harness or connector
  • Pump motor or pump motor circuit built into the brake actuator assembly

Comes on
  • INF Code 1159: SAE Code C1427
  • Electronically controlled brake system DTC

MONITOR DESCRIPTION

The skid control ECU (brake booster with master cylinder assembly) monitors the voltage of the ABS motor. When the ABS motor is normal and the ABS motor relay is turned off, the voltage of the ABS motor drops gradually due to rotational inertia; however, if the ABS motor is not turning and the ABS motor relay is turned off, the voltage of the ABS motor drops immediately. If the voltage of the ABS motor drops considerably quickly when the ABS motor relay is turned off, the skid control ECU (brake booster with master cylinder assembly) judges that the ABS motor is not operating and illuminates the MIL and stores this DTC.

MONITOR STRATEGY

Related DTCs

C1427: ABS pump motor stuck

Required Sensors/Components(Main)

Brake actuator assembly

Required Sensors/Components(Related)

Skid control ECU (brake booster with master cylinder assembly)

Brake actuator assembly

Frequency of Operation

Continuous

Duration

2 times

MIL Operation

Immediately

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever the following DTCs are not stored

None

Both of the following conditions are met

-

Skid control ECU (brake booster with master cylinder assembly) state

Initial check

After command to ABS motor relay on to off detection, 0.002 seconds passes

Met

TYPICAL MALFUNCTION THRESHOLDS

ABS pump motor voltage

Less than 1.3 V for 0.022 seconds or more within 0.024 seconds

COMPONENT OPERATING RANGE

All of the following conditions are met

-

Skid control ECU (brake booster with master cylinder assembly) state

Initial check

After command to ABS motor relay on to off detection, 0.002 seconds passes

Met

ABS pump motor voltage

Less than 1.3 V for less than 0.022 seconds within 0.024 seconds

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 a speed of 20 km/h (12 mph) or more for 1 minute.
  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 2019 - 2022 MY Avalon HV [04/2018 -        ]; 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) or brake actuator 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 2019 - 2021 MY Avalon HV [04/2018 - 08/2021]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): INITIALIZATION 2022 MY Avalon HV [08/2021 -        ]; 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.

PERFORM ACTIVE TEST USING TECHSTREAM (ABS MOTOR RELAY)

(a) Select the Active Test on the Techstream.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): DATA LIST / ACTIVE TEST

Chassis > ABS/VSC/TRAC > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Motor Relay

ABS motor relay

Relay ON/OFF

Operating sound of motor can be heard.

Chassis > ABS/VSC/TRAC > Active Test

Tester Display

Motor Relay

(b) Check the operating sound of the ABS motor relay when operating it with the Techstream.

Result

Proceed to

The operating sound is heard.

A

The operating sound is not heard.

B
B

GO TO STEP 3

A

2.

RECONFIRM DTC

(a) Clear the DTCs.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): DTC CHECK / CLEAR

Chassis > ABS/VSC/TRAC > Clear DTCs

(b) Turn the power switch off.

(c) Turn the power switch on (READY).

(d) Perform a road test.

(e) Check if the same DTC is output.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): DTC CHECK / CLEAR

Chassis > ABS/VSC/TRAC > Trouble Codes

Result

Proceed to

DTC C1427 is not output.

A

DTC C1427 is output.

B
A

USE SIMULATION METHOD TO CHECK

B

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY 2019 - 2021 MY Avalon HV [04/2018 - 08/2021]; BRAKE SYSTEM (OTHER): BRAKE BOOSTER (for HV Model): REMOVAL 2022 MY Avalon HV [08/2021 -        ]; BRAKE SYSTEM (OTHER): BRAKE BOOSTER (for HV Model): REMOVAL

3.

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - BRAKE ACTUATOR ASSEMBLY)

(a) Turn the power switch off.

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

OK:

The connector is securely connected.

(c) Disconnect the A35 skid control ECU (brake booster with master cylinder assembly) connector.

(d) Disconnect the A39 brake actuator assembly connector.

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

OK:

No deformation or corrosion.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A35-40 (+BM) - A39-10 (+BM)

Always

Below 1 Ω

A35-40 (+BM) or A39-10 (+BM) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

CHECK HARNESS AND CONNECTOR (GND TERMINAL)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A39-1 (MGND) - Body ground

Always

Below 1 Ω

*a

Front view of wire harness connector

(to Brake Actuator Assembly)
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)
OK

5.

RECONFIRM DTC

(a) Reconnect the A35 skid control ECU (brake booster with master cylinder assembly) connector.

(b) Reconnect the A39 brake actuator assembly connector.

(c) Clear the DTCs.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): DTC CHECK / CLEAR

Chassis > ABS/VSC/TRAC > Clear DTCs

(d) Turn the power switch off.

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

(f) Perform a road test.

(g) Check if the same DTC is output.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): DTC CHECK / CLEAR

Chassis > ABS/VSC/TRAC > Trouble Codes

Result

Proceed to

DTC C1427 is not output.

A

DTC C1427 is output.

B
A

USE SIMULATION METHOD TO CHECK

B

REPLACE BRAKE ACTUATOR ASSEMBLY 2019 - 2021 MY Avalon HV [04/2018 - 08/2021]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: BRAKE ACTUATOR (for HV Model): REMOVAL 2022 MY Avalon HV [08/2021 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: BRAKE ACTUATOR (for HV Model): REMOVAL