Brake light and no traction control light on with service brake system and stability sys disabled 2004 GMC Yukon XL 5.3

Ak0924 said:

The front brakes were compressed during a brake job to turn the rotors, the rear got compressed to turn the rotors and get new pads. No caliper hoses got pinched or abs wires got pinched. When I drive the vehicle with a scan tool I have correct speed to each of my wheel speed sensors. I tried bleeding the brakes, bleeding the abs and tapping the brake fluid reservoir to unstick the float. Problem still persists.

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rockola1971 said:

Wheel speed sensors input (supply) the wheel speed data to the ABS computer. The Wheel speed sensors do NOT receive any data. The wheel speed sensors have nothing to do with the speedometer and are NOT the signal source for your vehicle speed on the speedometer.
If you got a brake light and traction control light on then you have codes set!

Check the faces of the wheel speed sensors (they can be removed for inspection) to see if any damage like heavy/deep scratches or chips to their face are present. Also check for chunks of rust imbedded or sticking to their face. You need to monitor live data of wheel speed sensors, I suspect you have a problem with one not providing accurate or any data at all that agrees with the other 3.

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Ak0924 said:

I was reading the output from the wss for reference that there was no problem with them. There was in fact, No Codes! The problem ended up being a faulty sensor for the proportioning valve. Once replaced and system bled it went away.

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Ak0924 said:

I was reading the output from the wss for reference that there was no problem with them. There was in fact, No Codes! The problem ended up being a faulty sensor for the proportioning valve. Once replaced and system bled it went away.

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Ak0924 said:

I replaced the entire component

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