Nissan Repair: abs light on, nissan altima gle, nissan altima

Question
HI, I have a 1998 nissan altima gle sedan 4 door. The abs light comes on about 5 seconds after starting the car and remains on. The OB2 scanner shows no codes. I've read a ton of artical related to this problem... but hope to narrow down the possibles. If this is a wheel sensor gone bad how do you know which one? A lot of the articals said to change and bleed the brake fluid. Im greatful for any and all support related to this matter.
Thanks for helping people like me
Tom

Answer
Tom,

Brake fluid should be bled out every two years.  Most people do not do this.  ABS is sensitive to contamination and brake fluid that has lost its hydroscopic nature.  That is, the fluid gets humidity in it and then is gest spongy.  This ability to compress causes the ABS to go nuts and set a code.  Basically, change the fluid to Ford High Performance Brake Fluid and get three pints to do the job and bleed every line and you should be fine.  Now, there is the remote chance that you have had a harness to a wheel sensor get torn loose from road debris.  but, I am thinking the brake fluid first.  Disconnect the battery after you are done and leave the negative terminal off for aobut five minutes and the codes should clear.