Check Engine Light On. Help Please...

Check Engine Light Came On And We Put The Car On The Computer To Get Its Readings And Got The Code 1870- Transmission Components Are Slipping Took The Car To The Shop They Said That It Was Not My Transmission It Was The Fact That I Needed A Tune-up ( I Dont Know) I Tuned The Car Up And The Light Stayed Off For 2 Days Then It Came Back On When It Was Hot Out Side Turn Signals Didnt Work Nor Did The Lights Turn Off When I Put The Car In Park.... Could This Be A Computer Problem? Please Get Back With Me....

Did you pull the codes the second time?