Initially replaced the ice maker unit but that did not resolve the problem. Recommended diagnostics were inconclusive. I replaced the old water inlet valve with the new water inlet valve. The part is located on the outside back of the refrigerator/freezer, on the kick plate. Pull the refrigerator out, shut off the water, disconnect the water supply, disconnect the kick plate, disconnect the wiring harness, disconnect the ice maker water supply tube, and unscrew the one screw securing the valve to the kick plate. The new unit was a perfect match. Valve replacement took 45 minutes. Biggest challenges are shutting off/on the water supply - make sure the shut-off valve doesn't leak (since it likely hasn't been touched in years) - - and re-connecting the water supply to the water inlet valve - make sure the fitting doesn't leak (you may have to replace the compression sleeve around the copper tubing to get a water-tight fit. New valve resolved the problem fully.