AEM 30-1960 Plug & Play Fuel Ignition Controller 6 Channel - Manual (Page 3)

10-1960 FIC Quick Start Guide Rev B.doc 3
6) FUEL TUNING
Factory ECU’s have two running modes Open Loop (ECU does not trim fuel based on feedback
from O2 sensors) and Closed Loop (ECU trims fuel based on feedback from O2 sensors).
There is no “switch” or magical button on the F/IC that will force the factory ECU to operate in
either mode.
Open Loop Fuel Tuning
Fuel adjustments for open loop running conditions are made in the fuel map. A change in the
fuel map will result in a change in AFR.
Closed Loop Fuel Tuning
Closed loop fuel tuning requires a bit more work. Fuel adjustments for closed loop running
conditions are made by corresponding changes in both the Fuel map and the O2 map.
Adjustments in one map only will result in a temporary AFR change and large fuel trims.
Adjustments made in both maps will result in a permanent AFR change and factory like fuel
trims.
The table below can be used as a closed loop AFR target guide. The target AFR is listed in the
left column. The factory ECU will target the listed AFR when the corresponding value is entered
into the O2 map. NOTE: The fuel map will need to be adjusted in order to maintain low fuel
trims. Using the OBDII scanner, monitor the fuel trims live while making adjustments.
TARGET AFR O2 MAP VALUE
14.7 3.2
14.0 2.9
13.8 2.8
13.6 2.7
13.5 2.6
13.3 2.5
13.2 2.4
13.1 2.3
13.0 2.2
12.9 2.1
12.8 2.0
12.7 1.9
12.6 1.8
12.5 1.7
12.4 1.5
12.3 1.4
12.2 1.3
12.1 1.2
12.0 1.1
11.9 1.0
11.5 0.63
11.0 0.29
If further tuning help is needed be sure to visit the video gallery at
www.aempower.com for
comprehensive instructional videos.