ABS sound on take off

[98gpking]

ive seen a post like this before but lost it. anyways.

when i first start up the car and i take off. within the first 20 feet of driving it sounds like my ABS is kicking in or something it makes a weird vibrating rubbing noise. it dosent matter if im going 20mph or 2mph wheels turned or straight. is this sound just my ABS kicking in. or is there something else wrong. i had the exact same thing with my last grand prix and i drove it for 20k miles with no probs. i dunno if its a problem or just normal

[BNaylor]

IMO it is abnormal but others may have a different take on it. From what I understand it may be part of the ABS/EBTCM initialization which is performed under the following:

Originally Posted by GM Service Manual
The EBCM performs 1 initialization test each ignition cycle. The initialization of the EBCM occurs when 1 set of the following conditions occur:
Both of the following conditions occur:

* The EBCM detects that there is a minimum of 500 RPM from the PCM via a serial data message.
* The stop lamp switch is not applied.

OR
Both of the following conditions occur:

* The vehicle speed is greater than 16 km/h (10 mph).
* The stop lamp switch is applied.

The initialization sequence may also be commanded with a scan tool.

The initialization sequence cycles each solenoid valve and the pump motor, as well as the necessary relays, for approximately 1.5 seconds to check component operation. The EBCM sets a DTC if any error is detected. The initialization sequence may be heard and felt while it is taking place, and is considered part of normal system operation.

The EBCM defines a drive cycle as the completion of the initialization sequence.

However, here is the problem I have with any ABS related noise unless you are braking and circumstances require ABS to kick in. I have 3 GM "W" body cars to include a GTP and none of them ever make noise as described. And if they did I would troubleshoot the problem checking wheel sensor output at each wheel with an ABS capable scanner or other common test equipment.

[98gpking]

well im not 100% sure its even anything to do with the ABS system. in my moms jimmy when her ABS sensro fried out and she tried to hit the brakes it would make the same noise except hers was louder and longer. but again identical noises. i havent seen any problems with braking it stops fine and all and no lights or anything come on.


where would i go to for the scan tool. a dealer im assuming...OUCH!!! that would suck

[BNaylor]

Yeah the problem is a high end scan tool is needed like a GM Tech II or Snap On MT2500, etc. If you have a digital multimeter and a wiring diagram the wheel sensor speed output can be measured. Also, you can ohm out each wheel sensor. Resistance range is 800 - 1200 ohms with 1K being typical.

Some GP owners just live with the problem until something more definitive shows up like ABS and trac off lights.