How to Turn Off MDS on Hemi

Disabling MDS (Multi-Drive System) on Hemi engines requires specific procedures depending on vehicle model and year. This guide covers the most effective methods for turning off MDS functionality.

Understanding MDS Functionality

  • MDS automatically disables cylinders during light load conditions
  • Improves fuel efficiency but may cause performance issues
  • Can be disabled through various methods including software updates

Methods to Disable MDS

  1. ECU Flashing - Requires professional tuning and reprogramming
  2. Hardware Modifications - Involves physical connections to disable sensors
  3. Software Updates - Available through manufacturer updates or third-party solutions

Comparison of Disabling Methods

Method Cost Time Required Effectiveness
ECU Flashing $200-$500 2-4 hours High
Hardware Mods $100-$300 1-2 hours Medium
Software Update $50-$150 30 minutes Low-Medium

Step-by-Step Process

  • Connect OBD-II scanner to vehicle
  • Access engine control module settings
  • Locate MDS disable option in menu
  • Confirm changes and save settings

Important Considerations

  • Check local regulations before disabling systems
  • Verify warranty implications before proceeding
  • Consult professional mechanics for complex modifications