2001 Silverado ABS problem

My 2001 Silverado 4x4 has the ABS kicking on occasion on very slow stops for no apparent reason. Since this problem is intermittant, when I took it to a service center, the problem could not be duplicated by the technician. He did check the codes and it showed a DTC0281. (BRAKE SWITCH / STOP LAMP SW CIRCUIT) I am not certain if this code could be related to the problem I am experiencing.

Has anyone had a similar problem? Any help would be appreciated.

Reply to
Casey
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"Casey" wrote

I suspect that the code is "not" related to the problem, but you should get it fixed anyway. The code is indicating that you have either an open or shorted condition in the brake switch and/or associated wiring.

As for you other problem...it's a real common problem for GM vehicles. I'll just quote the relevant TSB...you can give the TSB number to the tech....and he should be able to fix it from there.

TSB # 03-05-25-007

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.

1.. 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). 2.. Disconnect both the front wheel speed sensor (WSS) connectors at the frame and harness. 3.. Place a Digital Volt Meter (DVM) across the terminals of each WSS connector. 4.. 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. 5.. 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.

6.. 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). 7.. 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. 8.. 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.

Hope this helps.

Ian

Reply to
shiden_kai

Thanks Ian.

Your help is much appreciated.

Casey

Reply to
Casey

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