AEM 30-4100 Digital Wideband UEGO Gauge - Manual (Page 3)

Page 3
vehicles. Its unique design makes precision AFR measurements possible over the
entire operating range.
UEGO sensors use a “current pump” to determine the actual oxygen concentration
within the sensing element or. The output is in the form of a very small current, which
varies depending on the air-fuel ratio. This is completely different from a narrow band
oxygen sensor, which directly outputs a voltage. The UEGO sensor design allows
measurement of the exact air fuel ratio over the entire operating range.
Each AEM UEGO sensor is individually calibrated and a resistor integral at the
connector body is laser trimmed with this value. This process replaces the traditional
“free air” calibration procedure when changing sensors and implements a sensor
specific calibration for unparalleled accuracy.
UEGO Sensor laser etched calibration resistor
INSTALLATION
Disconnect the negative (-) battery cable. There are four flying leads from the AEM
UEGO Gauge. Connection for two of the wires is mandatory and optional for the other
two, as shown below.
12V Power
Chassis Ground
0-5V Output
Serial Output
BOSCH LSU4.2 UEGO Sensor
Controller
UEGO
Gauge &
RED:
BLACK:
WHITE:
BLUE: