Lexus RX (RX 350L, RX450h) 2016-2023 Repair Manual: Brake System Control Module "A" System Voltage System Voltage High (C137BA3)

DESCRIPTION

If a malfunction is detected in the power supply circuit, the skid control ECU (brake actuator assembly) stores this DTC and the fail-safe function prohibits ABS operation.

This DTC is stored when the +BS terminal voltage deviates due to a malfunction in the power supply or charging circuit such as the battery or alternator circuit, etc.

The DTC is cleared when the +BS terminal voltage returns to normal.

WIRING DIAGRAM

Click here

CAUTION / NOTICE / HINT

PROCEDURE

(a) Check the battery voltage.

Standard Voltage:

NG

CHECK OR REPLACE CHARGING SYSTEM OR BATTERY

OK

(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors. OK: The connector is securely connected.

*a Front view of wire harness connector (to Skid Control ECU (Brake Actuator Assembly))

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

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

OK:

No deformation or corrosion.

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

Standard Voltage:

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

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

(b) Connect the Techstream to the DLC3.

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

(d) Operate the Techstream to clear the codes. Enter the following menus: Chassis / Brake/EPB / Trouble Codes.

(e) Press the DTC clear button.

(f) Turn the engine switch off.

NEXT

(a) Start the engine.

(b) Perform a road test.

(c) Read the DTCs following the prompts on the Techstream. Enter the following menus: Chassis / Brake/EPB / Trouble Codes.

(d) Check if the same DTC is output.

A

USE SIMULATION METHOD TO CHECK

B

REPLACE BRAKE ACTUATOR ASSEMBLY