Mark Salling, No Suicide Note, Body Discovered By Dumb Luck

Mark Salling did not leave a suicide note and cops have already combed his home, his car and the area where he hanged himself and nothing has turned up ... law enforcement sources tell TMZ.

The question we've been asking for hours ... how did police find Salling's body in a remote area by a riverbed? We thought cops may have tracked the body through his cellphone or GPS on his car, but that wasn't the case.

Law enforcement sources tell TMZ ... LAPD officers were in the area on an unrelated matter when they spotted Salling's car. As we first reported, a missing persons report had already been filed, so cops ran the plates, determined it was Salling's car, searched the area and found the body hanging from a tree.

TMZ broke the story, Salling committed suicide by hanging ... he had been suicidal for months awaiting sentencing after pleading guilty to child porn offenses.