ABS light on after being stuck

[needbigtruck]

I did a search for ABS and couldn't find anything, so I'll go ahead and ask. Got my truck stuck in the driveway trying to break up some of the snow piles. I guess it wasn't technically stuck since I finally got it out without assistance from another vehicle. While I was rocking it the ABS light came on and stayed on all the way down to the garage. Then when I left for work last night the light stayed on until I had driven about a mile, then it went off. Do you think I broke something, or did I just confuse the ABS system, spinning one front tire and not the other?

[BigLakeDMAX]

I've noticed ABS lights coming on in different vehicles I've driven after driving through water or deep snow. I believe it's the moisture interfering with the signal generated by the tone wheel on one or more of the wheels. Usually goes away after a couple of miles of driving. In your case, could be that you haven't driven far enough to clear out the snow and ice yet.

Good luck!

[Kennedy]

Likely because the front wheels were not spinning at near equal speeds.

When we run on the dyno, the ABS light will come on also...

[needbigtruck]

Good news, it didn't come on tonight on the way into work. thanks for the thoughts.

[Kennedy]

Basically, the brain sees one wheel sensor zero or low, with the trans OSS sensor signaling mph, and one wheel sensor reading too fast in a 3 wheel spinning situation.

In a dyno situation, there is mph signal (OSS) and there is no wheel signal from either.

[TxDoc]

From Truck Trend Magazine November/December 2003 on a 99 GMC Envoy that had ABS light coming on and off and did not throw a code:

"Several older GM trucks have experienced low speed ABS operation under normal driving conditions. The cause is corrosion buildup at the front wheel speed sensor mounting surfaces. The buildup increases the air gap between the sensor and hub reluctor ring, which triggers the sensor with changing wheel speeds. The increased gap causes incorrrect readings to be sent to the Electronic Brake Control Module, and the system reacts accordingly, by varying hydraulic pressure to the wheel in question. The correction involves testing the voltage output from each sensor, removing the sensors, and cleaning the sensor mounting surface at each hub. This will decrease the air gap, and bring the readings back within correct voltage parameters. The sensors may need to be replaced if excessively distorted. This condition WILL NOT set off a diagnostic trouble code.

This may not be your solution, but if nothing else pans out, you may try this fix.

[Kennedy]

This is a definite possibility for an older vehicle, but doubtful on anything 99 and newer.

Just went through this on my '96. Fix is quite simple, AND a little dab of dielectric grease should prevent reoccurrence.

The speed sensors are held in just like an old TH 350 kickdown cable, or a lot of (6.5 for example) crank sensors. The flange has a single lobe and a single bolt with the Oring being on the internal round part. The rust just heaves the sensor out a bit losing signal...