98 5.7L, Code P1870

Had the fuel pump and filter replaced by a dealer 4 days ago. Didn't have anyplace else to go, on vacation when it happened. Now 3 days later my SES light comes on. AutoZone check says code P1870 "Transmission Mechanical 4x4 Transfer Case Switch" but no other details. No symptoms to report. Any suggestions? Any lawyers out there wanna take up a suit against the dealer with me for repairs? LOL