How does the Dodge MDS system work?

How does the Dodge MDS system work?
The Dodge MDS (Multi-Displacement System) is a cylinder deactivation technology used in certain Dodge vehicles with Hemi engines. The MDS system is designed to improve fuel economy and reduce emissions by deactivating four of the eight cylinders in the engine during periods of low load or steady speed.
When the MDS system is activated, the powertrain control module (PCM) controls solenoids that manage special “dual mode” lifters, allowing the intake and exhaust valves of the deactivated cylinders to remain closed. This effectively turns the engine into a 4-cylinder engine, reducing fuel consumption and emissions. The transition between 8-cylinder mode and 4-cylinder mode is seamless and invisible to the driver.
It’s worth noting that not all Hemi-powered vehicles have the MDS system. Some high-performance variants, such as the 6.1L SRT or 6.2L Hellcat, do not have MDS. Additionally, Hemis with manual transmissions also do not have the MDS system.
Overall, the Dodge MDS system is an innovative technology that helps improve fuel economy and reduce emissions by deactivating four cylinders during periods of low load or steady speed.
Let me know if there’s anything else I can help with!

Why do MDS lifters fail?

The MDS lifter does not interface correctly with the custom camshaft, resulting in a lot of lifter ticking issues. There have also been many MDS lifter-related failures. The actual roller bearing inside the MDS lifter can seize up and fail, chewing its way through the lobe on the camshaft.

Can you turn off MDS on Ram 1500?

The MDS will be in a truck like a Ram with a Hemi for better fuel economy. Disabling the MDS can give you full engine power (maximum horsepower and torque) if you need it. If you want to permanently disable the MDS, buy a tuner. Otherwise it will take a few seconds to temporarily disable it.

How does a MDS lifter work?

That is what your mds system is activating these push pins sit in line with that hole now as oil flows over the body of the lifter. The oil collapses those pins. Now inside the lifter. There is a very

Can you disable MDS on Hemi?

Read. Now that we’ve read the file we’re going to go ahead and go to the settings to turn off the MDS. We’re going to go over to fuel. We’re going to go to lean fuel saving.

Does Hemi MDS save fuel?

MDS allows the engine to shut down 4 cylinders to conserve gasoline—at least that is the claim. As you can see, there wasn’t much gas savings running MDS. Just like my Charger 5.7L Hemi, the 8 speed transmission has far more to do with the gas savings than MDS.

Can you turn off cylinder deactivation?

Usually 99% of cars with that variable valve timing / Active Fuel Management cylinder deactivation, they can’t be simply turned off, you most likely have to retune the ECM and BCM, and maybe even the PCM as well so it counters and relearns to run like a car without the VVT/AFM.

How are the MDS solenoids controlled by the PCM?

To keep the valves from opening the PCM supplies power to the MDS solenoid for the cylinder it is shutting down. The solenoid directs oil pressure to the lifters for that cylinder, which pushes in the locking pins that allow the lifters to collapse so they no longer open the valves.

Is cylinder deactivation bad for an engine?

If the engine is equipped with a cylinder deactivation system, we face a new potential failure mode. Increasing the valvespring pressure or just increasing the amount of lifter movement at speed may be enough to overwhelm the oil pressure keeping the lifter in full operation.

How does MDS shut off cylinders?

The MDS solenoids direct oil pressure to the lifters for each cylinder and that pressure pushes in locking pins that allow the lifters to ‘collapse’, so they no longer open the valves. The ECU also shuts off fuel and spark to the cylinders.

How do you bypass MDS on Hemi?

How do I delete the MDS on my Gen 3 Hemi engine?

1. Option 1. Adjust the transmission settings. MDS is automatically disabled when you switch the transmission into Sport, Tow/Haul, or Manual shift mode.
2. Option 2. Use a Computer Programmer.
3. Option 3. Install an MDS delete kit or replace the MDS components individually.