i have a 2001 chevy tahoe what color and where is the vss located..

Speed Sense dk.green/white ECM

The ECM (Engine Control Module) is located near the battery, down low, between the fender and the fan under the black plastic cover. On the 4.3L, the VSS wire is at pin 3 in the connector labeled black. On the 4.8L, 5.3L, and 6.0L, the VSS wire is located in pin 50 of the red connector.