I have a 1998 Volvo V70 AWD and normally when i turn the engine on I get several warning lights such as engine management, transmission and ABS. Usually the speedo doesn't work and the mileage is --- . After a few miles usually the there is just the engine management light on and the speedo works. The codes indicate the left front wheel sensor but I have had that replaced to no avail. Is there a cost effective way of proceeding to repair or shall I give up? This would be a shame as the car has only done 95,000 miles.