Manuals through 2025 now available!
Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.
LEMON is the spiritual successor to CHARM, I recommend you try it!
Link:
lemon-manuals.la or
lemon-manuals.org.ua
(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)
Or, hide this message:
temporarily or
permanently
Long Term FT
Scan tool range
-23 to +16 percent. Long Term FT is derived from the Short Term FT 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 delivery is being reduced (decreased injector pulse width). A positive value significantly more than
0 percent indicates that a lean condition exists and the PCM is compensating by adding fuel (increased injector pulse width). Because Long Term Fuel Trim tends to follow Short Term FT, a value in the negative range due to canister purge at idle should not be considered unusual. The
powertrain control module's maximum authority to control Long Term FT allows a range between
-23 percent and
+16 percent. Fuel trim values at or near maximum authority may indicate an excessively rich or lean system.