Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual: ABS Solenoid Control Module Actuator Stuck On (C143A7E,C143A7F)

Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual / Brake / Brake Control / Dynamic Control Systems / Vehicle Stability Control System / ABS Solenoid Control Module Actuator Stuck On (C143A7E,C143A7F)

DESCRIPTION

The ABS solenoid relay is built into the skid control ECU in the brake actuator assembly.

The ABS solenoid relay supplies power to the holding solenoid and reduction solenoid.

The solenoid relay is turned on 1.5 seconds after the engine switch is turned on (IG), and is turned off if an open or short in the solenoid is detected by self-diagnosis performed when the vehicle is starting off.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C143A7E

ABS Solenoid Control Module Actuator Stuck On

When voltage at terminal +BS is 9.5 V or higher, solenoid relay is OFF, relay contact is ON continuously for 4.5 seconds or more.

Skid control ECU (brake actuator assembly)

C143A7F

ABS Solenoid Control Module Actuator Stuck Off

When voltage at terminal +BS is 9.5 V or higher and solenoid relay is ON, relay contact is OFF continuously for 0.22 seconds or more.
  • Wire harness and connector
  • Skid control ECU (brake actuator assembly)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • After replacing the skid control ECU (brake actuator assembly), perform "Calibration".

    Click here

HINT:

When C137BA2 and/or C137BA3 is output together with C143A7E and/or C143A7F, inspect and repair the trouble areas indicated by C137BA2 and/or C137BA3 first.

for C137BA2: Click here

for C137BA3: Click here

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (+BS TERMINAL)

(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:

Tester Connection

Condition

Specified Condition

A41-14 (+BS) - Body ground

Always

11 to 14 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

2.

CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A41-1 (GND1) - Body ground

1 minute or more after disconnecting the cable from the negative (-) battery terminal

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

3.

CLEAR DTC

(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.

Chassis > Brake/EPB > Clear DTCs

(e) Press the DTC clear button.

(f) Turn the engine switch off.

NEXT

4.

RECONFIRM DTC

(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.

Chassis > Brake/EPB > Trouble Codes

(d) Check if the same DTC is output.

Result

Proceed to

DTCs C143A7E and C143A7F are not output.

A

DTCs C143A7E and/or C143A7F are output.

B

HINT:

  • If a speed signal of 20 km/h (12 mph) or more is input to the skid control ECU (brake actuator assembly) with the engine switch on (IG) and the stop light switch assembly off, the ECU performs self-diagnosis of the solenoid circuit.
  • If the normal system code is output (no DTCs are output), slightly jiggle the connectors, wire harnesses, and fuses of the skid control ECU (brake actuator assembly).
  • If any DTCs are output while jiggling a connector or wire harness of the skid control ECU (brake actuator assembly), inspect and repair the connector or wire harness.
  • If no DTCs were output when reconfirming DTCs, checking for intermittent problems is necessary because it is suspected that the original DTCs were stored due to the poor connection of a connector terminal.
A

USE SIMULATION METHOD TO CHECK

B

REPLACE BRAKE ACTUATOR ASSEMBLY

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