October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.
Long Term FT
Scan tool range is
-23 to
+16 percent. Long term fuel trim is derived from the short term fuel trim value and represents a long term correction of fuel delivery. A value of
0 percent indicates that fuel delivery requires no compensation to maintain the
PCM commanded air/fuel ratio. A negative value significantly below
0 percent indicates that the fuel system is rich and fuel deliver is being reduced. A positive value significantly more than
0 percent indicates that a lean condition exists and the PCM is compensating by adding fuel.