Cummins

MM3 Tuner — Install & Tune File Programming

~8 min Video

The MM3 (and RaceMe Ultra) is a plug-in tuner for your Cummins that loads your custom tune and monitors the truck. Your device ships preloaded with your tune. Read the safety steps below before flashing, watch the install & programming video, and keep the reference manuals handy. Questions? Email info@empirediesels.com.

READ BEFORE FLASHING. Put a REAL high-quality battery charger on the truck at 12V / 15A and keep voltage above 12.5V for the entire flash — never use a jump box. If voltage drops below 12.5V, ECM damage can occur; do not flash under 12.5V. Use fresh batteries (under ~12 months old — battery quality has dropped hard since 2020, and older batteries may not hold flashing voltage). Always tune before removing any parts, and be gentle with every cable and connector.

Steps

  1. 1

    Use fresh batteries

    Make sure your batteries are newer — under about 12 months old. Since 2020, the average battery only holds proper tuning voltage for around a year, so older batteries may not sustain the voltage a flash needs.

  2. 2

    Unplug aftermarket accessories

    Unplug any aftermarket accessories and pull their fuses before you begin.

  3. 3

    Put a battery charger on the truck

    Connect a real, high-quality battery charger set to 12V and 15A to keep voltage above 12.5V while flashing. Do not use a jump box. If volts drop below 12.5V, ECM damage can occur — do not flash if under 12.5V.

  4. 4

    Tune before removing any parts

    Always tune the truck before removing parts — don't remove anything until tuning is complete. Be gentle with every hardware and cable connection: don't force anything, make sure each plug is fully seated, and double-check everything before programming.

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    Send us your stock files & get tuning support

    Check the email inbox you used on your original order — we send step-by-step instructions for sending your stock files to us. For any tuning support, contact Empire Diesels directly at info@empirediesels.com.