One problem related to brake antilock wheel speed sensor has been reported for the 2004 Volkswagen Jetta. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Volkswagen Jetta based on all problems reported for the 2004 Jetta.
Intermittently abs light comes on and stays on - at times for minutes, other times hours, even days; then goes off. At times it goes off with intervention as described below; other times by itself. At times the abs light turns on just prior to braking at low speeds/coasting; other times immediately after braking, sometimes along with a noise and brake pedal sinks slightly under my foot prior to brake being applied. Other times the light comes on while driving on the expressway or city streets. Since 12/2006 have taken to dealer numerous occasions and 2 other repair facilities with abs light on, diagnostics always show code 00283, left front speed sensor malfunction, and sensor replaced numerous times. Abs control module replaced 6/2009 at suggestion of dealer (requested old part and in my possession) to remedy problem, but abs light has come on again twice in 7/2009.