AEM Digital Wideband UEGO Gauge 304100 User Manual

ADVANCED ENGINE MANAGEMENT INC. 
2205 126th Street Unit A, Hawthorne, CA. 90250 
Phone: (310) 484-2322 Fax: (310) 484-0152 
http://www.aempower.com 
Instruction Part Number: 10-4000 Rev 4 
© 2004 Advanced Engine Management, Inc. 
 
 
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Installation Instructions for 
30-4100 
Gauge-Type UEGO Controller 
 
WARNING:
,!
This installation is not for the electrically or mechanically 
challenged! Use this sensor with EXTREME
 caution! If you are 
uncomfortable with anything about this, please refer the...

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Congratulations! The 52mm (2-1/16”) AEM Universal Exhaust Gas Oxygen (UEGO) 
Gauge features a digital readout and sweeping 24 color-coded light emitting diode 
(LED) display, providing immediate reference to the engine air fuel ratio (or lambda) in 
real-time. The AEM gauge is ideal for all vehicles including carbureted applications and 
engine dynamometers. A user-programmable 0-5V analog output is included and can 
be used with data loggers as well as most Electronic Fuel Injection (EFI)...

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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...

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Gauge-Type UEGO Controller Installation 
 
 
RED   
Connect to a switched 10-18 volt power source utilizing a 10A fuse. 
 
BLACK   
Connect to a clean power ground. 
 
*WHITE  
Connects to any Stand Alone ECU unit that accepts a 0-5 volt input. 
 
*BLUE  
Connects to a RS-232 com port for hyper-terminal data logging. 
 
*optional (see below) 
 
 
Analog Output 
If the AEM UEGO gauge is to be connected to an AEM EMS, the UEGO gauge’s 
WHITE Analog Output wire shall be connected to an EMS Lambda...

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Below is a list of AFR values that should be entered into the 02 Sensor #1(#2) Cal Table 
if inputting the analog signal to an AEM EMS. These calibration table(s) are found in the 
AEMPro software: Setup | Sensors | Oxygen Sensor | Oxygen Sensor #1(#2) 
 
When connecting to AEM’s EMS, make sure to verify that the O2 #1 Gain option is set 
so the voltage from the O2 #1 Volts parameter matches the voltage input at the EMS 
from the O2 sensor. An easy way to do this is to disconnect the UEGO...

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Connecting to Stand alone ECU’s  
When connecting to a third party EFI system, the AEM UEGO gauge’s WHITE Analog 
Output wire shall be connected to the analog O2 sensor input of that system. Consult 
the documentation provided with the system for detailed instructions. (for AEM EMS see 
page 4) 
 
Serial Output (optional) 
The serial output can be used for data logging when an EFI system is not accessible. 
To run the data stream, a RS-232 (DB-9) Female Receptacle shall be purchased. 
 
12345...

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Data logging with HyperTerminal 
UEGO Sensor 
If attempting to route the UEGO Sensor through a tight space, AEM recommends 
temporally removing the light grey latch from the Bosch connector, as shown below. 
  
 
Gently pull the latch out away from the UEGO Sensor connector 
 
 
UEGO Sensor connector without latch 
 
If the UEGO sensor is to be put through a conduit or firewall, a 1.05in (26.7mm) drill is 
required. Refer to the two diagrams above when reassembling the connector. 
 
A weld-in...

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time or plan on running leaded race fuel then you must mount the sensor at least 36 
inches or more downstream of the exhaust port as all of these can cause the sensor to 
overheat. On turbocharged engines the UEGO sensor must be installed after the turbo 
charger, if not, the pressure differential will greatly effect the accuracy of the unit. For 
accurate readings, the sensor must be mounted before catalytic converters and/or 
auxiliary air pumps. To prevent collection of liquids between the...

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P4
P3
P2
P1P0
ROTARY SWITCH
 
Calibration screw position settings 
 
The calibration will not be changed until the rotary switch reaches the middle of the new 
position. 
 
AEM Lambda Gauge Owners  
Because the Lambda gauge faceplate is calibrated for (
λ) and all other calibration 
positions are for AFR (Gasoline), AEM does not recommended changing the controller 
calibration, as instructed above. 
 
Below is the multiplier for calculating the Air Fuel Ratio (AFR) of common fuels from the...

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Specifications 
Gauge 
Supply Current (nominal): 1.3 amps 
0-5V Analog Outputs:  1 
Measuring Range:   0.751 to 1.143 Lambda 
Harness & Connector Temp Limit:  120C 
Sensor 
Type:  Bosch UEGO LSU4.2 
Accuracy: +/- 0.7% 
Exhaust Temp Limit:  1030C 
Cable & Protector Sleeve Temp Limit: 250C 
Connector Temp Limit:  120C 
Initial Warm-up Time:  Less than 20 seconds 
Weight: 80 grams 
Heater Current:  1.2A at 12.0V (each sensor) 
Mounting:  M18 X 1.5 thread, Torque to 30 ft-lbs 
Nominal Service...