This sporadic lighting up of the ABS warning light can mean your module is bad, or a portion of the module has failed. It could also mean that a short in the electrical portion of this system has formed. The only exact way to diagnose this type problem is to have VW service do a VAG-COM scan and this scan will direct the tech. to the exact problem and the correct repair. It could be as simple as a loose wheel speed sensor or a dirty one. If you have followed VW's 24 month brake fluid bleed that replaces the old fluid with brand new every 2 years, then your ABS valving and pump, ect. should be OK. If you have not changed the brake fluid, than rust or corrosion,ect can form in the very complex ABS valve system and pump and possible the brake calipers. If anyone has replaced low brake fluid in the reservoir with anything other than DOT 4 fluid, this could really cause trouble. Any one of these conditions could lead to an ABS warning light.
Good Luck, JK
Good Luck, JK
