99 Silverado ABS at slow speed

pickupman87 · January 26, 2015

I've got a 99' Silverado with about 110k on the clock. Recently started doing the ABS while going slow, normally when turning sharp but occasionally while going straight. Looks like there was some recall work on these trucks - would that still apply to a truck this old?

VIN is 2GCEK19T0X1133486

Thanks,
Pete

intheburbs · January 26, 2015

The wheel speed sensors get corroded, particularly in snow/rust-belt states.

Should be able to have it done - it is state-specific, though.

pickupman87 · January 27, 2015

The wheel speed sensors get corroded, particularly in snow/rust-belt states.

Should be able to have it done - it is state-specific, though.

I live in MN

I should mention that I purchased the truck used a few years back. I know on my last 99', the previous owner had the recall done so I had to pay for it myself. Is the best way to find out calling the dealership? Or is there an online app I can enter my VIN to see recall work performed?

durandetto · January 27, 2015

It's pretty simple to clean the sensor mating surface. Just pull the brakes off pull the Allen screw holding the sensor and twist and pull the sensor out of the bearing. Put something in the hole in the bearing and scrape the rust off the bearing. Put some sil glide or dielectric grease around the base of the sensor and reinstall. To find out which one is at fault put a dvom on the sensor wire and check the ac output of the bearing while spinning the wheel at 1 Rev per second. Good bearings should be putting out 300mv or more.

Sent from my LGLS990 using Tapatalk

sahls01gmc · January 27, 2015

4WD? If so, have you replaced the wheel bearings recently? Mine would do the same thing. The ABS would go off when I am turning into a parking spot. Turns out the bearing had enough play that it messed up the alignment for the ABS sensor when I turned, causing the ABS to think I was slipping when braking. New wheel bearings (that came with new ABS sensors), and haven't had a problem since!

durandetto · January 28, 2015

Bearings is the best way to do it but usually cleaning the mounting surface takes care of the problem. That's if the bearings have no play.

Sent from my LGLS990 using Tapatalk

SILVER SLED · January 28, 2015

If it happens a lot when turning sharp I would not rule out the wiring harness to the sensors/hubs. I can check for recall(s) tomorrow.

durandetto · January 28, 2015

When turning the wheels spin at different speeds so the ac output varies and if one sensor is weak it will cause a significant difference side to side causing the abs activation.

Sent from my LGLS990 using Tapatalk

durandetto · January 28, 2015

Usually when a bearing has excessive play the abs light will come on because the sensor will drop out completely. False abs activation happens because the reduced ac output isn't detected as a fault by the module so it acts as if one wheel is spinning at a different rate of speed.

Sent from my LGLS990 using Tapatalk

SILVER SLED · January 28, 2015

No other recalls, The recall for the speed sensor corrosion was done in 05. Still would not rule out wiring harness(s). Not nearly as common as the hub asm, but would hate to see you spend money on hub(s) and it end up being a harness.

pickupman87 · January 28, 2015

I appreciate the info guys. I'm not getting any abs light on the dash when this happens etc.

I replaced one of the hub assemblies a couple years back. I'll check the wiring and see if that looks OK.

Unfortunately because the trucks a 99 and I live in MN, the whole brake and hub area is extremely rusty.

sahls01gmc · January 28, 2015

I never had an ABS light go off on mine either when that happened. Both bearings had some pretty good play, so that was my indicator that they needed to be replaced.

durandetto · January 28, 2015

The module is unable to recognize the condition as a fault so the light will not come on. Clean the sensor mating surface or replace the suspect bearing. If you know someone with a scanner that reads live abs data you can figure out the problem sensor pretty easily, because one will drop from 6 or 7 mph to 3 while the other one is still reading 6 or 7.

Sent from my LGLS990 using Tapatalk