UltraGauge EM plus - AFR Commanded Ratio; Relative Throttle Position; Ambient Air Temperature; Accelerator Pedal Position

____________________________________________________________________________________________
Page 25/63 UltraGauge™ EM User Manual www.ultra-gauge.com
AFR
Commanded
ratio
Gauge name Range Units Abbreviation
AFR commanded ratio 0 to 1.999 AFR cmd
Fuel Air Commanded ratio. This is the value of Lambda requested by the ECM
= (Stoichiometric F/A ratio) / (Actual F/A ratio) >1 is lean, <1 is rich.
To determine the actual A/F ratio commanded, multiply this value by 14.64
For example. If this value is 0.90, the commanded Air Fuel Ration is 0.90* 14.64 = 13.17
parts air to one part fuel.
Relative Throttle
Position %
Gauge name Range Units Abbreviation
Throttle Pos % Rel 0 to 100 % Rel TP %
Relative or learned throttle position. A throttle position sensor may never return to its
minimum position, but instead closed throttle may always be greater than the TP Sensor’s
absolute minimum. This throttle position gauge adjusts for this true closed throttle position.
When the throttle is closed, this gauge will read 0% regardless of the details of the absolute
throttle position. The relative position value is calculated as follows:
Relative % = (TP output) – (TP output closed) X 100
(TP output max)
Example: If the output of the TP is 1V when closed and 10 volt when wide open, an output of
5V would be: (5-1)/10*100 = 40%
Note: This means that this gauge will likely never reach 100%
Ambient Air
Temperature
Gauge name Range Units Abbreviation
Ambient Air Temp ºF
-40.0 to 419.9
ºF
Amb ºF
Ambient Air Temp ºC
-40.0 to 215
ºC
Amb ºC
Outside ambient air temperature
Accelerator
Pedal Position
Gauge name Range Units Abbreviation
Accel Pedal Pos1 %
0 to 100 %
Ped1 Pos%
Accel Pedal Pos2 % Ped2 Pos%
The percentage that the throttle Accelerator Pedal is pressed. This is the absolute output from
the accelerator pedal position sensor as a percent of the sensor’s max value. The un-pressed
and fully pressed positions will likely not be equal to 0% and 100% respectively. For
example, the physically un-pressed position may correspond to an absolute position of 8%.
Pedal Position 2 is for vehicles with a second throttle Position Sensor
Throttle Position
Commanded
Gauge name Range Units Abbreviation
Throttle Pos % Cmd 0 to 100 % Cmd TP %
The percent throttle requested by the ECM. Used on electrically driven throttles.
When the driver presses the accelerator pedal, the ECM converts the output of the Pedal
position sensor to a corresponding throttle position commanded %. The electrical throttle
position drive then opens the throttle by the commanded %.
Engine Oil
Temperature
Gauge name Range Units Abbreviation
Engine Oil Temp ºF
-40.0 to 419.9
ºF
Oil ºF
Engine Oil Temp ºC
-40.0 to 215
ºC
Oil ºC
Engine Oil temperature. Supported by few vehicles (<1%)
Fuel Injection
Timing
Gauge name Range Units Abbreviation
Fuel Injection Timing -210 to 302
degrees
FI º
Fuel Injection timing degrees relative to Top Dead Center (TDC). Positive degrees indicate
before TDC, negative degrees indicate after TDC.