Brand: AEM PERFORMANCE ELECTRONICS
Category: Controller
Document Type:
Language: EN
Manual for 30-0300 - Troubleshooting and error codes + PDF Download
Uploaded: April 8, 2025, 1:51 p.m.
Manual Publish Date: 2017-07-12
Warranty Summary
AEM PERFORMANCE ELECTRONICS warrants the 30-0300 for 12 months against defects in material and workmanship, limited to repair or replacement of the part.
The AEM 30-0300 X-Series UEGO Gauge operation is managed through two buttons: MODE and SEL.
- MODE Button: Cycles through display options (3 or 4 digit, AFR, Lambda, O2%, AEMnet CAN ID).
- SEL Button: Selects the displayed option.
- Calibration: Offers resistor trim (rCAL) and free air calibration (ACAL) modes. Resistor trim is factory default. Free air calibration requires sensor removal and is for advanced users.
- Display Modes: Configurable for AFR, Lambda, or O2%. Faceplate is reversible for Lambda scaling.
Refer to the manual for detailed steps on navigating menus and performing calibrations.
Troubleshooting and error codes
| Problem | Solution |
|---|---|
| Gauge displays "bAtt" | Check vehicle's battery voltage. Ensure it's above 12V (engine off) or 13.8V (engine running). |
| Display shows "- - - -" | Normal in lean conditions (engine off, decel). Check for exhaust leaks or sensor placement near open air. |
| Free air calibration reports "FAIL" | Ensure sensor is removed from exhaust and in fresh air, free of exhaust or chemical fumes. |