Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Supply Voltage Circuit IG Open (C123A14)

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Brake / Parking Brake / Electric Parking Brake System / Supply Voltage Circuit IG Open (C123A14)

DESCRIPTION

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

Note

C123A14

Supply Voltage Circuit IG Open
  • Diagnosis Condition:

    Engine switch on (IG)

  • Malfunction Status:

    When the ECM is communicating via CAN communication, IG power is not input to the skid control ECU (brake actuator sub-assembly).

  • Detection Time:

    Approximately 15 seconds
  • Wire harness and connector
  • Skid control ECU (brake actuator assembly)

DTC stored

An electric parking brake system malfunction is displayed on the multi-information display.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • The electric parking brake may still operate up to 20 seconds after the engine switch is turned off. Before disconnecting connectors or fuses, turn the engine switch off and wait 20 seconds or more.
  • After replacing the skid control ECU (brake actuator assembly), perform "Calibration".

    Click here

  • When replacing the skid control ECU (brake actuator assembly), operate the electric parking brake switch (electric parking brake switch assembly) as the parking brake indicator light (red) blinks when the engine switch is first turned on (IG).

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (IG1 TERMINAL VOLTAGE)

(a) Disconnect the A41 skid control ECU (brake actuator assembly) connector.

(b) Turn the engine switch on (IG).

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A41-45 (IG1) - Body ground

Engine switch on (IG)

11 to 14 V

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Actuator Assembly))
OK

REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
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