ABS Light - any tips

2001 Impala 3.4

Driving along on turnpike at 70 mph, ABS light comes on.

Start the car, light is off, then after 10 mins driving, ABS Light comes on. The routine goes on for 2 weeks, now light is on all the time.

I read something about tire pressure, and making sure all tires are equal pressure. Then I found something about a TBS Bulletin about intermittant ABS Light. I have an OBD scanner, but no codes found. I tired looking in the past forum subjects, but couldn't find anything. Sorry if this was already addressed, but does anyone got an easy fix? Brakes seem to be fine.

2001 Impala 3.4

Driving along on turnpike at 70 mph, ABS light comes on.

Start the car, light is off, then after 10 mins driving, ABS Light comes on. The routine goes on for 2 weeks, now light is on all the time.

I read something about tire pressure, and making sure all tires are equal pressure. Then I found something about a TBS Bulletin about intermittant ABS Light. I have an OBD scanner, but no codes found. I tired looking in the past forum subjects, but couldn't find anything. Sorry if this was already addressed, but does anyone got an easy fix? Brakes seem to be fine.Try dissconnecting your neg battery terminal for 30 seconds and hook her back up, this should cure the problem, if not you have a bad wheel sensor gone or starting to go the sensor is made into the wheel bearing and you have to replace the whole unit $400 and up, also check the wiring going to each of the sensors in the wheel bearings, a broken wire will also cause this.

I have had the same problem before. Just reset you tire pressure monitor from the radio and turn the car off and on again. Sometimes the light comes on for me if I am in heavy stop and go traffic or going down the highway at 140 km/h then slowing down to a 20 km/h traffic jam. It has to do with the wheel bearings turning at different speeds.

Well, I replaced the thermostat this weekend (which was a royal pain) and just for fun had disconnected the neg terminal for 3 hours to "clear" any codes. It did clear the codes. And the ABS light was cleared. But it did not last long...maybe a day or 2 and the light came back on.

But...in Pittsburgh, it was warm today ~50 or so degrees. And the light was on in the morning (~25 degrees) and off when I came home. I am thinking...effects on tire pressure due to temp swing, and then issues with tire pressure sensor and the ABS issue with tires spinning at different speeds. I'll add some air to the tires, its been a while since I checked them so I will add some air if needed, reset through radio and see how it goes. Car has 70k miles. It seemed to be cold weather related, came on when cold. Then if I stoped at a store after work and came home, light would be out from store to home...so I am thinking, driving 30 miles highway, tires heated up...at least it seems logical to me...at least, better than putting the key in the ignition, turning the lights on and off 3 times. Whats next, flash the high beams twice and hit the horn? C'mon, it sounds so rediculous. If it does work, I'd love to meet the engineer who developed that.

The tire pressure monitoring function isn't that sensitive. A few psi variation will not set off the ABS light. I would bet you have a hub bearing with a flaky ABS wheel speed sensor or a loose/dirty connection at one of them. These sensors can be affected by temperature, humidity, weather, etc...

wheel sensor. Have fun determining which one though.....

If I were to somehow attemp to look for the faulty sensor or sensors - I am thinking its one sensor as its such a transient issue, sometime light comes on, sometimes its not and my experience with electronic seonsors is once their "fried" they are done for good - not transient performance.

Where are the sensors and what do they look like? I am thinking maybe loose or dirty connection, at least its worth looking at, as I can tell you, there is no way I am dumping $400 (what someone else listed) into the ABS sensor, as the brakes are working fine - light or no light.

Thxs

This is a sensor issue, whether its a wiring problem, or an internal problem within the hub assembly is the question. A general reader will not retrieve these codes. You have to find a shop(or dealer) that has a good scanner to retrieve these codes. From there you can trace it down.

Take a good look at the wires coming from the front hubs. They are notorious for getting damaged and having intermittent. Pull the tires, start the car and wiggle these wires. If the wire is loose, it will set the ABS/TRAC light. This test can only be done of course, if you ABS light is off to start with.

Wire - I went through the same problem with my 01 Impala LS (started around 80K - finally fixed at 105K), and it turned out to be the ABS sensors which are built into the hub bearing assembly. It took me two dealers, but I finally found one who read the codes and found the right bearing throwing the code. Good idea to check the wiring to the sensors - I was hoping that was my issue, but the wires are better than they seem. I replaced both (not a bad idea to replace this kind of thing in pairs) for $250 (rockauto.com), using BCA aftermarket bearings. The dealer quote was 600 bucks. Hope things work out for you.

I resolved my ABS light issue accidently when I found my carpet was wet below the front of back "seat" cushion vertical area where the sensor wire pass thru is. Sealed the leak in drain plug cup (knock-out was loose). Dealer wanted $360 to replace sensor rear passenger wheel. When connection block was dry, the light went out, it has never triggered the light since. Check if you have a wet carpet any where, can't hurt..D`