I have a 2001 Buick Century Custom. ABS, Trac and service engine light come on after 45 minutes and stay on. I have replaced left rear main bearing/speed sensor twice and wiring harness with same result. Dealer is lost as it keeps sending them back to same location. What should I try next.

SOURCE: trac, Abs and Service engine light on - 2001 buick Century

The ABS system including pump may be faulty which is quite common. You will have to take this to dealership or mechanic. Either there is a bad pump or a fault in the electrical system

SOURCE: what sensor lights will come on when a wheel

Hello mobrien.
Depending on what your car is equipped with. Antilock brake systems work in conjunction with traction control.So if the antilock system has a fault, traction control will also default system off. It may also turn on low pressure in a tire if your car has that feature.
In the bearing/hub assembly on your Buick there is a sensor ring that rotates with the axle. A sensor is positioned close to that ring to read wheel speed.
A failed bearing doesn't necessarily damage the sensor, nor will a bad sensor mean the bearing is bad. But on your vehicle if one fails the assembly must be replaced as a unit.
I hope this answers your question.If you have another leave it in a comment and I will answer you.

KL

SOURCE: 2001 buick century 3.1 ltr abs light on , service

You could be encountering computer failure. Needs to be looked at.

Testimonial: "thank you wasnt sure maybe ill take it back"

SOURCE: Service Vehicle, Trac Off, & ABS lights 2001 Buick Century.

I just put in new fron pads in my 2000 buick century and the track off and the anti lock brake light and the service engine soon stays on

SOURCE: brake problems with 2002 buick

You most likely have a bad wheel speed sensor. The first thing to do is inspect the wires coming down to the front wheel speed sensors and check for any obvious damage (this is VERY common). If you don't see anything that looks obviously damaged or broken, then you will have to scan your Powertrain Control Module (PCM) and your Antilock Brake System Module (ABS) for fault codes that will lead you to the cause of the problem.

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