AEM 30-6905 Universal Programmable EMS-4 - Manual (Page 246)

Page 246 of 279 EMS-4 Install and Tuning Guide_Rev 1.6
loads because of the sensor's inaccuracy outside the stoichiometric rangeand at high exhaust
gas temperatures. However, O2 feedback can be used at high engine loads with a quality
UEGO sensor.
O2 FB Rate
Units: mS Description: O2 feedback base timer for both proportional and integral terms. This is
how often the air fuel ratio is referenced to determine the necessary correction. A smaller
number gives a faster response by effectively increasing the gain. This should be the same as
the sampling rate of the O2 sensor being used. A typical value is 65.59 mS.
O2 FB Max RPM
Units: RPM Description: O2 feedback will operate when the RPM is below this value but is not in
cranking mode. Limits O2 feedback control above the user-defined rpm.
O2 FB Control
Units: On/Off Description: Enables closed loop O2 feedback and the O2 Target parameter.
After the Fuel Map has been tuned, O2 feedback can be enabled for automatic tuning
adjustments.
O2 FB Accel Inhibit
Units: microseconds Description: O2 feedback threshold for accel fuel. O2 feedback will operate
when the current Fuel Trim (Accel) amount is below this value. Because the acceleration fuel
delivers an abundance of fuel in a very short amount of time, O2 feedback can ignore it to avoid
possible air fuel ratio overshooting. However, using this functioncan still allow O2 feedback
when there is a very small amount of acceleration fuelemployed.
O2 FB Update Rate
Units: mS Description: O2 feedback delay after the acceleration fuel has been disabled.
Thisfunction allows the mixture to be restored without using O2 feedback in order toprevent air
fuel ratio overshooting. A typical value is 196 mS.
O2 FB Decel Inhibit
Units: mSDescription: O2 feedback delay after the decel fuel function has been disabled.Typical
Use: This function allows the mixture to be restored without using O2 feedback in order to
prevent air fuel ratio overshooting. A typical value is 196 mS.
O2 FB Accel Clear
Units: On/Off Description: Sets O2 feedback to zero after both accel and decel fuel functions
havebeen implemented. After utilizing accel/decel fuel, the next condition will typically be
different from before. This function is used to allow the O2 feedback to clear its memory and
start from zero again.
O2 FB DFCO Clear
Units: On/Off Description: Sets O2 feedback to zero after decel cut fuel have been
implemented.After utilizing decel cut fuel, the next condition will typically be different from
before.This function is used to allow the O2 feedback to clear its memory and start from zero
again.