The "Locked PCM" Problem: Why You Can't Just Tune Your 2019+ RAM 1500
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You just put 35-inch tires on your 2019–2024 RAM 1500.
The speedometer is off. The shift points are sluggish. You want a little more power to turn that rubber.
You go to buy a handheld tuner, just like you did for your old truck.
Stop.
You are about to run into the Locked PCM.
Starting in 2015 (and locked down even tighter in 2019), RAM encrypted the Powertrain Control Module.
If you plug a standard tuner into the OBDII port, it will read "Error" or "Locked."
To tune these trucks the "old school" way, you have to physically remove your computer, mail it to a shop to be "unlocked" (voiding your warranty), and then reinstall it.
But there is a better way.
Enter the Inline Module (Piggyback).
Devices like the Edge Pulsar (for Hemi) and JB4 (for Hurricane) plug in between the computer and the engine harness. They modify the signals in real-time to add power, calibrate tires, and disable MDS—all without ever "hacking" the factory computer.
In this guide, we explain how these modules work and why they are the safest way to tune a modern RAM.
Compare Performance Upgrades
Just Throttle Response or Real Horsepower?
|
Upgrade |
Function |
Installation |
Best For |
|
Edge Pulsar |
Tuning + Control. |
Easy. (Piggyback). |
2019-24 Hemi. Adds 30HP, disables MDS, adjusts tire size. No PCM swap needed. |
|
JB4 Tuner |
Boost Controller. |
Easy. (Piggyback). |
2025+ Hurricane. The gold standard for turbo tuning. Safely adds boost for massive gains. |
|
Pedal Commander |
Throttle Response. |
Instant. (Gas Pedal). |
Daily Drivers. Eliminates "Dead Pedal" lag. Does not add horsepower. |
|
DiabloSport Trinity |
Full Flash Tune. |
Hard. (PCM Swap). |
Hardcore Builds. Requires swapping the computer. Mandatory for superchargers/cams. |
|
Pulsar LT |
Feature Control. |
Easy. (OBDII). |
Calibration. Adjusts tire size/TPMS/Auto Start-Stop only. No power gains. |
Frequently Asked Questions (Tuners)
How do I disable the MDS (4-Cylinder Mode) on my Hemi?
You need an Edge Pulsar.
The 5.7L Hemi shuts down 4 cylinders on the highway to save gas, often causing a droning sound (especially with aftermarket exhaust).
-
Edge Pulsar: This module plugs directly onto your PCM and gives you a button combination on the steering wheel to Disable MDS instantly. It is the only way to do it without a full unlocked PCM swap.
Will a tuner void my warranty?
It depends on the device.
-
Inline Modules (Pulsar/JB4): These do not overwrite the factory computer. If you remove the device before going to the dealer, it is generally undetectable and leaves no "flash counter" trace.
- PCM Swaps (DiabloSport): Yes. Swapping your computer or flashing the ECU is detectable and can void your powertrain warranty.
What is the difference between Pedal Commander and a Tuner?
- Pedal Commander: Changes how fast the throttle opens when you press your foot. It makes the truck feel faster, but the engine makes the same horsepower.
- Tuner (Pulsar/JB4): Changes timing, fuel, and boost maps. It actually increases the horsepower and torque of the engine at Wide Open Throttle.
Unlock the beast.
Fix the lag and add the power RAM left on the table. Shop our verified collection of 2019–2026 RAM 1500 Tuners.