One problem related to check engine light on has been reported for the 2003 Volkswagen Beetle. The most recently reported issues are listed below.
The contact owns a 2003 Volkswagen Beetle. While driving approximately 70 mph on normal road conditions, the oil pressure and check engine warning indicators illuminated intermittently on the instrument panel. The vehicle was taken to an independent mechanic, who stated that the failure was related to oil sludge and the sending unit. The vehicle was repaired. The failure mileage was 99,600 and current mileage was 100,000. 4/01/09 there was sludge in the oil pan and the check engine light stayed on constantly. Updated 04/06/09.