ABS trouble

thiv73 · March 25, 2004

Been having a problem with the ABS brakes on my y2k Silverado. It's gotten worse over the past year or so. When I'm travelling at low speeds, like going through a parking lot or nearing a stop-light, the ABS cycles like I'm on ice. There are times when simply lifting my foot off the pedal and pushing back in works. Then there are times when it cycles and won't let me stop till I've hit a curb. Pulling the fuse to the ABS system has worked for the time being, but I've lost cruise control in the process. Anyone had similar problems? Know what the fix is? Thanks.

JJ

blackburb · March 25, 2004

Here is the TSB for this:

Make : CHEVROLET Model : SILVERADO Year : 2000

Service Bulletin Num : 030525007 Date of Bulletin: OCT 01, 2003

NHTSA Item Number: 10004310

Component: SERVICE BRAKES, HYDRAULIC:ANTILOCK

Summary:

ANTILOCK BRAKE (ABS) ACTIVATION AT LOW SPEEDS. *TT

TSB's and recalls can be searched for at:

http://www-odi.nhtsa.dot.gov/cars/problems/

bartlanz · March 25, 2004

Im haveing a simlar prob with my 98n tahoe, any TSB on it?

asepgrad98 · March 25, 2004

Antilock Brake (ABS) Activation At Low Speeds (Clean Wheel Speed Sensor Mounting Surface) #03-05-25-007 - (09/29/2003)

Antilock Brake (ABS) Activation At Low Speeds (Clean Wheel Speed Sensor Mounting Surface)

2002-2004 Cadillac Escalade, Escalade EXT

2003-2004 Cadillac Escalade ESV

1999-2004 Chevrolet Silverado

2001-2004 Chevrolet Suburban, Tahoe

2002-2004 Chevrolet Avalanche

2003-2004 Chevrolet Express

1999-2004 GMC Sierra

2001-2004 GMC Yukon, Yukon XL

2003-2004 GMC Savana

2003-2004 HUMMER H2

Condition

Some customers may comment on ABS activation at low speeds, usually below 8 km/h (5 mph). Upon investigation, the technician will find no DTCs set.

Cause

The cause of this condition may be an increased air gap between the wheel speed sensor and the hub reluctor ring due to rust and debris built up on the sensor mounting surface.

Correction

Measure AC voltage and clean the wheel speed sensor mounting surfaces.

Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in the General Information sub-section of the Service Manual (SI Document ID #899664).

Disconnect both the front wheel speed sensor (WSS) connectors at the frame and harness.

Place a Digital Volt Meter (DVM) across the terminals of each WSS connector.

Rotate the wheel clockwise approximately one revolution per second. The minimum reading should be at least 350 ACmV's. If the reading is less than 350 ACmV's, remove the wheel speed sensor. Refer to the applicable Wheel Speed Sensor Replacement procedure in the ABS sub-section of the Service Manual. Plug the WSS bore in order to prevent debris from falling into the hub during service.

Clean the WSS mounting surface on the hub to remove any rust or corrosion using a wire brush, or equivalent.

Important

Make sure that the sensor sits flat on the hub. Check the sensor flange against a straight edge to ensure flatness. If the sensor flange is distorted, replace the sensor.

Apply a thin layer of bearing grease to the hub surface and sensor O-ring prior to sensor installation. Use ONLY Wheel Bearing Lubricant, P/N 01051344 (Canadian P/N 993037).

Install either the original sensor or a new one in the hub. Ensure that the sensor is seated flush against the hub. Refer to the applicable Wheel Speed Sensor Replacement procedure in the ABS sub-section of the Service Manual.

Place the DVM across the sensor terminals and recheck the voltage while rotating the wheel. The voltage should now read at least 350 ACmV's.

Parts Information

Part Number

Description

01051344

(Canadian P/N 993037)

Wheel Bearing Lubrication - Tub

Parts are currently available from GMSPO.

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation

Description