Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001XOF8
Model Year Start: 2022 Model: Avalon HV Prod Date Range: [08/2021 -           ]
Title: PARKING BRAKE: ELECTRIC PARKING BRAKE SYSTEM (for HV Model): C123A14; IG1 Circuit Short to Ground or Open; 2022 MY Avalon HV [08/2021 -        ]

DTC

C123A14

IG1 Circuit Short to Ground or Open

DESCRIPTION

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

Note

C123A14

IG1 Circuit Short to Ground or Open

Both of following conditions are met:

  1. Power switch on (IG)
  2. When hybrid vehicle control ECU communicates with main body ECU (multiplex network body ECU) via CAN communication, IG power supply voltage is not received for approximately 15 seconds.
  • Wire harness and connector
  • Parking brake ECU (brake actuator assembly)

DTC stored

An electric parking brake system malfunction is displayed on the combination meter assembly.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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

PROCEDURE

1.

READ VALUE USING TECHSTREAM (IG1 VOLTAGE)

(a) Read the Data List according to the display on the Techstream.

Chassis > Electric Parking Brake > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

IG1 Voltage

IG voltage value

Min.: 0.0 V

Max.: 25.5 V

Power switch on (IG): 11.0 to 14.0 V

Changes in proportion to auxiliary battery voltage

Chassis > Electric Parking Brake > Data List

Tester Display

IG1 Voltage

Result

Proceed to

The value of IG1 Voltage is between 11 and 14 V

A

None of the above conditions are met

B
B

GO TO STEP 4

A

2.

CLEAR DTC

(a) Clear the DTCs.

Chassis > Electric Parking Brake > Clear DTCs

(b) Turn the Power switch off.

NEXT

3.

CHECK DTC

(a) Check for DTCs.

Chassis > Electric Parking Brake > Trouble Codes

Result

Proceed to

C123A14 is output

A

C123A14 is not output

B
A

REPLACE PARKING BRAKE ECU (BRAKE ACTUATOR ASSEMBLY)

B

USE SIMULATION METHOD TO CHECK

4.

CHECK HARNESS AND CONNECTOR (IG TERMINAL VOLTAGE)

(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 A39 parking brake ECU (brake actuator 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

A39-26 (IG) - Body ground

Power switch on (IG)

11 to 14 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

CHECK HARNESS AND CONNECTOR (EGND TERMINAL)

(a) Turn the Power switch off.

(b) Disconnect the A39 parking brake ECU (brake actuator assembly) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A39-2 (EGND) - Body ground

Always

Below 1 Ω
OK

REPLACE PARKING BRAKE ECU (BRAKE ACTUATOR ASSEMBLY)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR