P1870 is a Transmission Internal Component Slipping. No real way to tell what component without physical inspection.
AKA your transmission is probably due for a rebuild. However you could try draining the fluid, replacing the filter and fluid and seeing if that helps. Take a close look at the fluid coming out and see if it's burned or full of junk. Or do a flush and fill to get more fluid changed.
Monday, October 20th, 2008 AT 2:01 PM