2002 pontiac grand prix abs and trac off lights are on. I already had the hub and wheel bearing assembly replaced. Light went off for 3 day and now it is back on again. What else could it be?

THE ABS WHEEL SPEED SENSORS ARE PART OF THE WHEEL BEARING ASSEMBLIES.THEY ARE A 2 WIRE HALL EFFECT SENSOR. DISCONNECT THEY HARNESS AND USE A DVOM (DIGITAL VOLT OHM METER) SET ON AC VOLTAGE AND SPIN THE WHEEL WHILE CONNECTED TO THE SENSOR IN THE WHEEL BEARING. IF YOU DONT GET A READING REPLACE WHEEL BEARING. IF YOU DO ITS A WIRING ISSUE BETWEEN SENSOR AND ABS MODULE.

Its possible but the more common problem is a bad or loose wheel Bearing. The easiest thing to do would be to scan the ABS computer to see what the code is. Than focus on that part or that wheel. You can jack up the wheels and see if the wheel bearings are loose. If you have one with a lot of play than that could be the problem. While you have the wheels off the ground visually check the harness and connector. If you see any corrosion or broken wires than you found the problem. Here's another clue. If the light comes on when you start the car and then goes out and stats out until you start to move than its usually a wheel bearing issue. If the light comes on when you star the car and never goes out than its more likely to be a connection issue, broken wire, or bad sensor (which is part of the wheel bearing hub assembly). Let me know what you find!

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Had the same problem with my 2002 Lincoln LS, it was a bad wheel speed sensor. The right front wheel bearing had some play in it, so I had the hub assembly replaced. The hub assembly comes with a new wheel speed sensor attached. After I replaced the hub assmbly with sensor, the ABS and Traction Control lights went off. No problem since!

Hi, the wheel speed sensor and tone ring are built into the bearing/hub assembly. Make sure the new hub contains an ABS wheel sensor and the cable was properly connected. If it is properly connected, the new hub may be defective.

Its a bad wheel speed sensor. It is built into the hub. If you did not have the problem prior you probably damaged the sensor in the new hub. Unfortunatley that means replacing it again. You need to have someone scan the vehicle while driving it to see if it is in fact that one or another just happen to go out. the scanner must have gm data listing.

I agree that it is more then like the the hub bearing assembly that also houses the speed sensor I would first check that there is no damage to the wiring that goes to the hub bearing that could be easy repaired, or debri that has been caked in between the sensor & the hub, use an air preesure to clean it out. Hub bearings are very expensive, so try this first. Good luck

Either someone damaged a sensor for the ABS/TRAC control, or the replacement parts are not compatible with the ABS system.

bad front bearing/abs sensor The sensor is part of the bearing,or the wires are bad so that when you steer it open circuts and thinks the wheel is stopped. need to read codes or use a scan tool with live data to see which wheel the computer thinks is stopping. then look at that wheel for problems

hey, ihad this problem with abx and trac off light on all the time even after having replaced the wheel bearing twiice. how i fixed it was to replace the wiring harness and poof issue resolved. a technical service bulletin is available for this issue

Def the wheel bearings/hub/speed sensor. I just bought a new wheel bearing comes with the hub and speed sensor as one. Runs about 80-100 dollars though but abs/traction light went off and stays off now.