ABS pulsating when braking

Good afternoon,

This is a common issue when the sensor mounts are dirty and that effects the operation of the ABS. It does it mostly when you are almost to a stop.

I would remove the sensors at the wheels and clean the mounts with a wire brush.

Roy

Hi,

Chances are you have a faulty wheel speed sensor and the vehicle thinks one wheel (or more) is locking. As a result, the ABS is actuated.

If you have a live data scanner, you can check wheel speeds for each wheel. You will see one that is off as far as speed. Or, you can check each wheel speed sensor with a multi meter. Here is a link that shows how it is done:

https://www.2carpros.com/articles/abs-wheel-speed-sensor-test

Here is a link that explains in general how one is replaced:

https://www.2carpros.com/articles/how-to-replace-an-abs-wheel-speed-sensor

If you find one of the sensors is bad, here are directions specific to your vehicle for replacement. The attached pics correlate with the directions. Note: You did not indicate if it is 2 or 4wd. This info is for a 2wd vehicle. If it is 4wd, let me know.

____________________________________
Front Wheel

2000 Lexus Truck RX 300 FWD V6-3.0L (1MZ-FE)
Speed Sensor, Front
Vehicle Sensors and Switches Sensors and Switches - Brakes and Traction Control Wheel Speed Sensor Service and Repair Procedures Speed Sensor, Front
SPEED SENSOR, FRONT

pic 1

REMOVAL

pic 2

1. DISCONNECT SPEED SENSOR CONNECTOR
a. Remove the front wheel and front fender liner.
b. Disconnect the speed sensor connector.

pic 3

2. REMOVE SPEED SENSOR
a. Remove the bolt, flexible hose and speed sensor harness clamp from the shock absorber.
Torque: 29 Nm (300 kgf-cm, 21 ft. lbs.)
b. Remove the resin clip from the shock absorber.
c. Remove the bolt and speed sensor harness clamp to the body.
Torque: 5.0 Nm (55 kgf-cm, 48 inch lbs.)
d. Remove the bolt and speed sensor from the steering knuckle.
Torque: 8.0 Nm (82 kgf-cm, 71 inch lbs.)

INSTALLATION
Installation Is in the reverse order of removal.
1. AFTER INSTALLATION, FILL BRAKE RESERVOIR WITH BRAKE FLUID AND BLEED BRAKE SYSTEM
2. CHECK FOR LEAKS FRONT SPEED SENSOR COMPONENTS

________________________________________

Rear - For both 2 and 4 wheel drive vehicles

2000 Lexus Truck RX 300 FWD V6-3.0L (1MZ-FE)
Speed Sensor, Rear
Vehicle Sensors and Switches Sensors and Switches - Brakes and Traction Control Wheel Speed Sensor Service and Repair Procedures Speed Sensor, Rear
SPEED SENSOR, REAR

pic 4

REMOVAL

pic 5

1. DISCONNECT SPEED SENSOR CONNECTOR
a. Remove the front wheel and front fender liner.
b. Disconnect the speed sensor connector.

pic 6

2. REMOVE SPEED SENSOR
a. Remove the bolt, flexible hose and speed sensor harness clamp from the shock absorber.
Torque: 29 Nm (300 kgf-cm, 21 ft. lbs.)
b. Remove the resin clip from the shock absorber.
c. Remove the bolt and speed sensor harness clamp to the body.
Torque: 5.0 Nm (55 kgf-cm, 48 inch lbs.)
d. Remove the bolt and speed sensor from the steering knuckle.
Torque: 8.0 Nm (82 kgf-cm, 71 inch lbs.)

INSTALLATION
Installation is in the reverse order of removal.
AFTER INSTALLATION, CHECK SPEED SENSOR SIGNAL

______________________________

Let me know what you find or if you have other questions.

Take care,
Joe