Mini Maxx Tuner Authoritative Technician's Support

① Emissions Control System Disablement (Core Function)

Rewrites the Engine Control Unit (ECU) program so the DPF (Diesel Particulate Filter), EGR (Exhaust Gas Recirculation) system, DEF (Diesel Exhaust Fluid)/SCR (Selective Catalytic Reduction) system, and CAT (catalytic converter) can be physically removed without bypassing the diagnostic logic, triggering the Check Engine Light (CEL), or generating Diagnostic Trouble Codes (DTCs).

② Professional Performance Tuning

The device comes preloaded with multiple factory-optimized tuning levels. Depending on the vehicle, model year, and selected tuning level, it can deliver gains from 0 to 300 HP while optimizing turbo boost and fuel-injection logic to substantially improve torque output and throttle response.

③ Real-Time Parameter Monitoring and Fault Diagnosis

Functions as an auxiliary digital gauge display and monitors more than 20 critical engine operating parameters in real time, including exhaust gas temperature (EGT), turbo boost pressure, transmission temperature, and coolant temperature. It also supports one-touch reading and clearing of vehicle-wide DTCs for routine maintenance and performance-tuning diagnostics.

④ Practical Auxiliary Functions

Supports speedometer recalibration for non-stock tire sizes, adjustment or removal of the factory speed limiter, and custom activation or deactivation of hidden factory functions on supported vehicles such as the 6.7L Cummins, including high-idle mode and seat-belt chime disablement.

📌 Quick Buying Guide

• 2012 and earlier vehicles → ✅ Mini Maxx V1 | Maximum value for the money
• 2013–2019 vehicles → ✅ Mini Maxx V2 | The only compatible Mini Maxx option
• 2019+ Powerstroke / 2016+ Duramax / 2021+ Cummins → ❌ The entire Mini Maxx range is incompatible | 👉 Switch to a newer EZ Lynk smart tuning device for dedicated compatibility, wireless updates, and a lower failure rate
• Unsure about compatibility → 💬 Contact dedicated technical support for a free compatibility check

Step 1: Mount the Device

Secure the suction-cup mount in a suitable position on the windshield, then slide the Mini Maxx device into the mount's T-slot.

Step 2: Connect the OBDII Adapter

Locate the OBDII diagnostic port beneath the driver's-side dashboard and firmly insert the adapter plug.

Step 3: Connect the Power Wire (⚠️ Critical)

Connect the power wire to the vehicle fuse box using the supplied fuse tap.
Make sure the fuse tap is installed on the "dead side" of the fuse socket.

Step 4: Connect the HDMI Cable

Use the HDMI cable to connect the Mini Maxx device to the OBDII adapter.

Step 5: Power On and Install the Tune

Move the power switch on the adapter to the BAT position.
Turn the vehicle key to the ON position (⚠️ do not start the engine).
Open the main menu → select Install Download → follow the on-screen instructions to complete installation.

📘 Complete Installation Manuals (PDF)

🔹 General Pre-Installation Checklist (V1 / V2)

• Vehicle battery voltage is at least 12.5V; connecting a battery charger is strongly recommended.
• If another brand of tuner was previously installed, the ECU has been completely restored to stock.
• Complete the tuning process before physically removing the DPF, EGR, DEF, or other emissions-control components.
• The SD card has been formatted according to the table above and contains the required tune files.

* This update is only for the V2 version. Do not use it on a Mini Maxx V1 tuner.

Pre-Update Preparation

• Hardware: Windows computer + Micro SD-to-USB adapter
• SD Card: 2GB/4GB, SanDisk or Kingston, FAT format, named “MINI MAXX”

Update Procedure

1. Use “Return to Stock” in the tuner menu to uninstall the tune.
2. Download the V2 update package and extract it on the computer.
3. Copy all extracted files and subfolders to the root directory of the SD card.
4. Insert the SD card into the tuner, select “Update Firmware” from the menu, and wait for the process to finish automatically. Do not interrupt power.
5. After the firmware update is complete, connect the tuner to the vehicle, select “Install Download,” and reflash the tune.

🔸 Power and Display Problems

Symptoms: Black screen, frozen on the startup screen, or unable to power on.
Possible Causes:
① Battery voltage below 12.5V
② Loose or damaged HDMI/OBDII cable
③ CAN bus interference caused by an OBDII Y-splitter
Solutions:
① Charge the battery
② Disconnect and reconnect all cables
③ Remove other OBDII devices so the Mini Maxx is the only connected device

Communication Failure (Black Screen / Screen Stays On) - Troubleshooting Mind Map

🔸 SD Card Logic Errors (Codes 399 / 327)

Symptoms: The screen displays "Insert SD Card" or error code 399/327.
Possible Causes:
For Mini Maxx V1:
① The file is not in the root directory.

For Mini Maxx V2:
① SD card capacity exceeds 8GB
② Incorrect SD card format (exFAT/FAT32 instead of FAT)
③ Tune files are not in the root directory
Solution: Prepare the card again in strict accordance with the V1/V2 SD card requirements above.

SD Card Error - Troubleshooting Mind Map

🔸 Tune Installation Failure

Symptoms: No performance gain after installation and the boost gauge reads 0.
Possible Cause: The tune failed to write to the ECU.
Solution: Open Menu → Settings → Tune Status. If it shows "Not Installed," rerun Install Download while maintaining stable battery voltage.

🔸 LML (2011+) Engine Limitations

• V2 does not support dual-tank configurations; the rear tank will be disabled.
• The boost-gauge function is unavailable.

🔸 Error Code 312 (2007.5–2010 LMM)

1. Open "Display Settings."
2. Press and hold the lower-left corner of the screen for 10 seconds, then enter unlock code 0468.
3. Select "Reset Unit."
4. Immediately open "Install Download" without selecting the vehicle year again.

🔸 Error Code 316

Cause: The ECU contains remnants of another tuner's programming.
Solution: Take the vehicle to a dealership or qualified repair facility and use a factory diagnostic tool, such as IDS, to completely reflash the ECU to stock.