Try to get the codes red out it will give you the problem area without checking the entire system but if you want to check this on your own, first visual inspection of the wires going to the wheels-front wire come down from harness near drain tubes for the wiper cowl along the body to the spindle, at the rear they come down the pass side fornt of fuel tank then run along the rear susp, for all us 94 & up you will not have connectors at the rear hubs the sensors are one piece with the harness earlier cars were harness and two sensors with conectors. To clean the rear sensors, press rear pads back with channel lock pliers no need to remaove pads from calipers unless they need serviced and cleaned as well clean pads along the edges and the hardware as well,pins&shims, remove the two 13mm caliper bolts swing caliper away from disc and let it sit on the lower sring mount of the suspension. Find the adjustment star wheel for the park brake shoes, locate it at around just off of 12 o'clock. The purpose of the extra hole you will see on you rotor is for the adjustment, click downwards to slaken off shoes, remove 10mm disc pin , and use a rubber hammer to tap on disc with shoes backed away correctly the disc should pop off. Use some soap and water to clean sensor, and pulse wheel, DO NOT use air as this will get into your lungs not good! Do not scrape any components as you will damage them, after the wash blow dry, lube the parking brake pivot and check that the hub mounting surface is clean to aloow proper mounting of disc, take the time to sand down the rust ridge inside the rotor where the park brake shoes sit can be noisy, may as well do it all while the car is in pieces, put it back together in reverse order, click star wheel upwards until you can not turn it anymore the disc will be locked with the shoes on, now back off star wheel click downwards 4 clicks that is the proper distance for the shoes to be away from the inside of the drum or adjust until the drag sound correct when the disc is turned by hand, do not leave it to tight it will be noisy, as soon as you fell you have this adjustment set reach in the car and check the hand brake function. This would complete not just the ABS cleaning but the park brake as well as rear pads. If you are not comfortable DO NOT try this! If you get your codes I can tell you what they are. Hope that helps boys sorry its a bit long but I do not want to leave any parts out.