X-SERIES UEGO GAUGE - Instruction Manual - 30-0300

Nov 4, 2026

Uploaded by Connor

Instruction manual for the AEM X-Series Universal Exhaust Gas Oxygen (UEGO) gauge P/N 30-0300, used with the Bosch LSU4.9 wideband sensor. Describes four-digit central readout and 24-color LED AFR/lambda display, selectable display precision, and support for lambda, AFR, and O2% modes. Provides safety guidance about vehicle electrical integration, calibration responsibility notes, wiring requirements, and pinouts for power/IO, optional CAN/AEMnet and RS-232 outputs, plus sensor harness connections and operational button setup.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages13

Reading Time33 min

AccessFree to download

Warning and Notes

Gauge Overview and Features

Kit Contents

Optional Accessories

Wiring Installation Diagram

Gauge Connections and Harness Integration

Connector A: Power/IO Pinouts

Connector B: Bosch LSU4.9 UEGO Sensor Pinouts

Important Notes on Wiring

Operation and Display Modes

Instruction Manual P/N 30-0300 X-SERIES UEGO GAUGE Bosch LSU4.9 STOP! -READ THIS BEFORE INSTALL OR USE! WARNING: THIS INSTALLATION MAY REQUIRE WELDING OR INTEGRATION INTO A VEHICLE'S ELECTRICAL SYSTEM. DAMAGE TO SENSITIVE ELECTRONICS, FIRE, OR EXPLOSION MAY OCCUR IF PROPER PRECAUTION IS NOT TAKEN. IF THEREIS ANY DOUBT, DO NOT ATTEMPT THE INSTALLATION AND CONSULTA PROFESSIONAL. NOTE: IT IS THE RESPONSIBILITY OF THE ENGINE TUNER TO ULTIMATELY CONFIRM THE CALIBRATION USE FOR ANY PARTICULAR ENGINE IS SAFE FOR ITS INTENDED USE. AEM HOLDS NO RESPONSIBILITY FOR ANY ENGINE DAMAGE THAT RESULTS FROM THE MISUSE OF THIS PRODUCT. The 52mm (2-1/ 16”) AEM X-Series Universal Exhaust Gas Oxygen (UEGO) Gauge features a four digit central readout and sweeping 24-color-coded 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 0-5V analog output is included and can be used with data loggers or aftermarket ECUs including the AEM Infinity Engine Management System (EMS) . In addition, an AEMnet (CAN bus) and serial data stream are also available for logging or mixture control purposes . The X-Series Digital Wideband technology is US Patent \#9,575,030. Features · X-Digital Technology · Free air or resistor trim calibration modes · Fast response, 20ms typical · 2-1/ 16" / 52mm outer diameter mounting · 8.0:1 to 20.0:1 AFR / 0.55 to 2.00 Lambda · Configurable 3 or 4 digit precision display mode · Lambda, AFR, O2 % display modes with reversible faceplate · Black bezel/faceplate supplied; Silver/white available as optional purchase · Locking connectors · Supports vehicle/system voltages up to 16V · Supports Bosch LSU4 .9 Sensor · 0-5V Analog Output · AEMnet (CAN bus) Output · Serial RS-232 Output | KIT CONTENTS | | | --- | --- | | PN | Description | | 10-0300 | INST, X-SERIES UEGO GAUGE | | 35-0300 | GAUGE ASSY , X-SERIES AFR GAUGE | | - | RED INSULATED BUTT CONNECTORS (4) | | 35-4005 | WELD-IN BUNG,02 SENSOR 1214 MILD STEEL | | 35-8618 | NUT, KNURLED, M4x0.7 (2) | | 35-8614 | BRACKET, X-SERIES GAUGE | | 35-3430 | PWR/IO CABLE, X-SERIES GAUGE | | 35-3427 | SENSOR CABLE, X-SERIES GAUGE LSU4 .9 | | 35-8617 | RUBBER BAND, X-SERIES GAUGE | | 35-2004 | SENSOR, WIDEBAND UEGO BOSCH LSU 4 .9 | | *OPTIONAL* ACCESSORIES | | | --- | --- | | PN | Description | | 30-0300-ACC | BEZEL, X-SERIES GAUGE SILVER FACEPLATE, X-SERIES AFR WHITE | | 30-2355-200 | NOWELD UEGO CLAMP KIT, 1.75" to 2.00" | | 30-2355-250 | NOWELD UEGO CLAMP KIT, 2.25" to 2.50" | | 30-2355-300 | NOWELD UEGO CLAMP KIT, 2.75" to 3.00" | | 30-2355-350 | NOWELD UEGO CLAMP KIT, 3.25" to 3.50" | | 30-4008 | WELD-IN FINNED BUNG, O2 LONG, STAINLESS STEEL | | 35-4001 | BUNG PLUG,02 SENSOR | AEM Performance Electronics, 2205 126th Street Unit A, Hawthorne, CA 90250-Phone: (310) 484-2322 [http://www.aemelectronics.com](http://www.aemelectronics.com) Wiring Installation Diagram Gauge Connections The X-Series UEGO gauge is supplied with a Power/ IO wiring harness (A) and a UEGO sensor harness (B); the harnesses are connected to the gauge as shown below. The UEGO sensor harness simply needs to be routed to the UEGO sensor whereas the Power/ IO harness will require further integration into the vehicle. The minimum Power/ IO connections required to operate the gauge are switched 12V (5A fuse) and ground. Please reference the diagrams and information on the provided for further detail. 7/12/2017- DOCUMENT NUMBER: 10-0300 © 2017 AEM Performance Electronics ConnectorA-Power/ IO | Pin | Color | Description | | --- | --- | --- | | 1 | RED | Switched 12V Power (5A Fuse) | | 2 | BLACK | Power Ground | | 3 | GREEN/BLACK | AEMnet- / CANL (Optional) | | 4 | WHITE/BLACK | AEMnet+ /CANH (Optional) | | 5 | BLUE | Serial / RS-232Output
(Optional) | | 6-8 | - | Not Used | | 9 | WHITE | 0-5V Analog Output Positive

FAQs

What safety precautions are required before installing the X-Series UEGO gauge?

Installation may require welding or integration into the vehicle electrical system, and misuse can damage sensitive electronics or create fire/explosion risk. If there is any doubt, do not attempt installation and consult a professional.

How does the gauge display AFR and lambda, and what outputs are supported?

The gauge provides a four-digit central readout and sweeping 24-color-coded LED display for immediate real-time AFR/lambda reference. It includes 0–5V analog output plus AEMnet (CAN bus) and serial RS-232 output options.

What are the minimum power connections needed to operate the gauge?

The minimum required connections are switched 12V power (5A fuse) and ground. Additional connections (such as CAN/AEMnet and serial) are optional as listed in the pinout.

Nov 4, 2026

Uploaded by Connor