Tech Tip: Light Braking Causes ABS Modulation

Tech Tip: Light Braking Causes ABS Modulation

During light braking on Acura vehicles, a wheel sensor that detects a faulty or intermittent low-speed signal can make the ABS control unit "think" the affected wheel is turning slower than the rest. To make all wheels turn at the same speed, the ABS then modulates the brake fluid pressure to that wheel, causing the pedal kickback to be felt with normal ABS activation.

During light braking on Acura vehicles, a wheel sensor that detects a faulty or intermittent low-speed signal can make the ABS control unit “think” the affected wheel is turning slower than the rest. To make all wheels turn at the same speed, the ABS then modulates the brake fluid pressure to that wheel, causing the pedal kickback to be felt with normal ABS activation.

Applies to: All Acuras with ABS, except SLX.

To diagnose this condition, you first need to know which wheel sensor is sending the faulty signal. Use your tester to pinpoint the sensor on systems without an ABS reservoir. On systems with an ABS reservoir, jump the ABS inspection connector with a multimeter. Once you’ve located the sensor in question, perform the following steps.

Service Procedure:
1. Measure the air gap between the wheel sensor and the pulser. Refer to the appropriate S/M for specs and measuring details. See Fig. 1.
2. If the air gap is OK, check the pulser for dents or scratches.
3. If the pulser is OK, check the resistance between the wheel sensor’s terminals. Refer to the appropriate S/M for specs.
4. If the resistance is OK, check the wheel sensor circuit for an intermittent short to ground.
5. If the circuit is OK, replace the wheel sensor.

Courtesy of American Honda Motor Company.

You May Also Like

ADAS Calibration Aborts

Knowing the common “hiccups” can save you time and money.

If you have invested in the fixtures and scan tools to perform ADAS calibrations, you know most systems will walk you through the entire process. But, what happens when you follow the directions and the process still won’t initialize or complete or a malfunction light comes on?

Chassis – Ride Control

Learning how to read the tire and communicate your findings is the key to ride control.

Myers Tire Supply Introduces MTS Xpresstm

The innovative solution to consolidate purchases and control inventory costs.

Albemarle, Ford Form Strategic EV Production Agreement

Albemarle will supply more than 100,000 metric tons of battery-grade lithium hydroxide for future Ford EV batteries.

Trailer Brakes and Bearings

From trailer brakes to wheel bearings, there are plenty of ways that your customer’s trailer can add to the profitability of your operation. 

Other Posts

Driveshaft Center Support Bearings

Spotting center support bearing problems can happen from the moment you put the vehicle in gear to pull it into a bay.

Air Compressors for Shocks (VIDEO)

There are four items you need to pay attention to when installing a compressor for an air ride system. Sponsored by Wabco.

Mercedes Airmatic Suspensions

Diagnostic tips to aid your repair efforts.

Charging More for Brake Jobs

Here’s why charging more for brake jobs keeps customers coming back.