why are the abs and 4-wheel drive lights on on 2005 Mercury Mariner

abs and 4-wheel drive lights are on. how much are these repairs usally.

Asked by for the 2005 Mercury Mariner
Many sensors on modern cars multi-task and report to more than one computer. A sensor failure or inaccurate signal may be responsible for both lights or circuits being affected. In either case a scan tool will be required to diagnose the circuit further and figure out the source of the problem.
I have the same issue. I was told that there was a wheel speed sensor for my abs. These are found behind the wheels. The problem is finding which one has malfunctioned.
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Same thing happened on my '06. There's an ABS "tone" ring, aka sensor wheel, at each wheel located on the hub end of each halfshaft. Mine failed on the front passenger side and both front rings are easy to see just by taking a peek with a flashlight. I saw mine was cracked right away and it spun free on the hub. Definitely a DIY repair for $15.00 or so at your local parts store. Dealer probably wants a couple hundred bucks and would more than likely try to sell you a halfshaft as well. Just replacing the shaft would be easier and more profitable for the dealer. Some helpful web videos available to help you out. Naturally the problem could be something else but it appears this failure is common on this vehicle. The aftermarket part will more than likely outlive the vehicle. (Go figure.........I have a Chrysler with almost a quarter million miles on it and NEVER had this happen. Yea Ford!!)