"Suggestion for The ABS Light problems on 2003 Subaru Legacy Wagon"

2003 Subaru Legacy Wagon Right Side View

I have a 2003 Subaru Legacy wagon and the abs light came on a few weeks ago. I looked in the manual and it said I might have a bad battery. But I checked that and my battery was fine. Any suggestions?

Answer: An ABS system is designed to read the wheel speed from cogs on the driveshafts with a Wheel Speed Sensor (WSS). When the ECU notices a speed difference in the wheel speeds it arms the system, and when a skid or lock up is noticed, the ABS module will pulse the faster WSS wheel as to slow without locking up. Usually the ABS light will trigger during a awful event, like flying off jumps or dips with the brakes engaged, and usually stay on if someone moved the wheel while it was on a lift. The ECU reads a movement of only one WSS and triggers the warning in the PROM (programmable side of your computer).
Simple quick do it yourself test:
Disconnect the ground cable from the battery using a 10mm wrench
Wait 10 minutes
Connect Ground cable to battery
Start car and confirm light is off
Drive car and see if it comes back on

If yes:
Take it to a Subaru Dealer, you might have a bad WSS or a serious brake concern

If no:
Drive your Subaru and enjoy