Tuning Your 2019-2020 GM Truck With A DiabloSport Predator 2

Tuning is a paramount instrument in optimizing your vehicle’s performance, and adding aftermarket products like an intake or exhaust compounds the problem. So while the ability to bypass or adjust factory settings can be managed through an inline control module, there are still horsepower and drivability resolutions left on the table without a proper tuner, like the DiabloSport Predator 2. One small problem, though: General Motors locked us out.

So why would a company like GM with a history of producing tunable muscle cars and trucks break tradition and start a global ECM lockdown on all E90 ECM’s for full-size GM 5.3L L82 and L84 and 6.2L L87 trucks? Well, one word, fear. As the world becomes more digital regarding remote diagnostics and autonomous features, the thought of safety quickly arises. The idea of someone hacking a moving vehicle, rendering the occupants helpless, has probably kept a few GM executives and attorneys up at night.

Never Say Never

GM not only locked us out, but claims were made that it could never be unlocked, and any tampering could lead to the ECU being bricked — never to be used again nor a cheap item to replace. Well, as the popular kid’s cartoon character Ms. Frizzle would say, “never say never.” Thankfully, companies like DiabloSport took the crazy hair childhood bus driver’s advice and kept cracking (pun intended). 

Michael Litsch, Brand Manager of Diablosport said, “Cracking the code was a two-part process. First, we spent a few months working to unlock the PCM so it could be flashed in the vehicle through the OBDII port. From there, we spent several weeks developing the process where we get the customer’s ECU in here, unlock it and get it back to them in the shortest possible time frame.”

Most ECU’s require a virtual handshake agreement to get past certain elements to alter or change mappings. GM went one step further and installed a completely “unhackable” PCM inside the ECM. To bypass GM’s Fort Knox PCM, DiabloSport requires you to send your ECM to have it modified. DiabloSport then ships the ECM back to you overnight, making sure your truck is ready to rock before the next workday.

The Engine

The 2019-2020 full-size GM truck lineup is no slouch. The L82 and L84 5.3L engines make between 283-294 rear-wheel horsepower and still push over 300 lb-ft of torque. The L87 6.2L engine reigns supreme, with 355 horsepower and 397 lb-ft of torque. The automatic 10-speed transmission, a joint venture between Ford and Chevrolet, found behind the L84 and L87 engines is a fan favorite for a good reason. This transmission holds massive power and still shifts seamlessly, emulating the feel of a continuously variable transmission (CVT) instead of an automatic.

GM’s Gen V LT engine is a reliable platform that makes good power and torque, but there’s more to be had. The Diablosport Predator 2 allows for more horsepower, torque, and allows the user to turn off AFM and DFM on command. 

Not Without Fault

While the engine and transmission seem like a great combo of power and reliability, there’s plenty of new features that irk the driving enthusiast and neuter the available performance on deck. The first one is the speed limiter. The speed limiter is fixed in place, and the argument of if tire size or driveshaft length dictates it doesn’t matter. The fact remains these trucks will rarely get above 105 mph from the factory.

Active Fuel Management (AFM) and Dynamic Fuel Management (DFM) are another problem. The systems allow the motor to reduce from eight cylinders down to four cylinders. This reduction in cylinders also plays a vital part in how the transmission responds to shifting. Most owners report a clunky tip in and tip out during driving attributed to DFM.

The ability to disable AFM/DFM and the Auto Start/Stop system is huge, as most truck enthusiasts would rather not deal with these. – Michael Litsch

The 2019-2020 GM full-size trucks also experience a sense of pedal lag on the accelerator. The extremely firm pedal feel does not mirror the input the throttle blades should be receiving. When letting off the fun pedal, engine braking is excessive and engages with a “clunk.” The nuisances of safety and efficiency raising features tend to lack efficacy, if any at all. The horsepower loss from spark removal due to programmed intake air temperatures (IAT) is the straw that breaks the camel’s back.

Predator 2: Take Your Weapon

DiabloSport recognizes the potential of these vehicles and the ability to tune is their modus operandi. Since DiabloSport’s ability to enter GM’s E90 ECU, it has addressed complaints and optimized your vehicles’ performance via its canned (preprogrammed) tunes. All this unlocked potential is easily accessible through the Predator 2 handheld tuner.

Using the 7222-R Predator 2, you can access and adjust speed limiter, tire pressure monitoring system (TPMS), tire size, axle ratios, diagnostic trouble codes (DTC), disable auto start/stop and control Dynamic Fuel Management (DFM). This product is similar to the DiabloSport Pulsar LT but with the added ability to change ECM mapping. The Predator 2 allows you to insert and extract ECM tunes with ease by using the five-button interface and high definition 2.8-inch color screen. Predator 2 also allows T2 logging, allowing you to tune to the threshold of the motor via knock sensing.

So how much of a difference can a tune make? Well, simply put, a lot. Showcasing the Predator 2 ability, DiabloSport created a canned tune via numerous T2 logs. The logs provided enough data for DiabloSport to make changes to the engine and transmission mappings. The changes resulted in more horsepower on top, more torque on the low end, and increased smooth drivability.


The Predator 2 uses high-speed OBD II data logging that can monitor and log up to 16-plus parameters. RPM, IAT, load, boost pressure, exhaust gas temperature (EGT), spark…you name it. The data can be viewed in real-time or logged to create the perfect map for your vehicle and its modifications. The use of logging IAT temps before and after runs allowed DiabloSport to reduce spark knock, a significant contributor to lost horsepower.


Everyone loves numbers, and seeing an increase from the factory on horsepower and torque numbers is always good. In stock form with nothing more than pump 93 and a tune, DiabloSport was able to pump up the low-end 22 lb-ft of torque, something you will feel when daily driving. It also increased 14 horsepower on the top end, reflected in knocking off .5 seconds in the 1/4-mile!

The Predator 2 improves horsepower and torque at every level. With 93 octane in the tank, the LT engine picked up 16.3 horsepower and 23.7 lb-ft of torque.


While high performance is not everyone’s forte, drivability on a new truck should be. Unfortunately, the factory drive-by-wire mapping is slow to respond, resulting in a dead pedal feel. DiabloSports’ canned tune will fix both variables in the drive pedal mapping. The tune will also help the transmission by firming up line pressure and shift times to give you quick engagement and quick gear changes on the throttle.

“The drivability changes are immediately noticeable, starting with the throttle response,” Litsch explained. “The pedal feel is improved quite a bit, and users will feel that right away. Once they roll into the throttle, they will notice increased power and smoother acceleration versus the stock tune.”

Custom Maps

While DiabloSport doesn’t have time to custom-tune every vehicle, its Chip Master Revolution (CMR) program enables tuners and individuals to purchase their tuning software and fully tune and create custom maps. Unlike canned tunes, a custom map is perfect for those looking to optimize a bolt-on or forced induction vehicle without the hassle and cost of going to a complete standalone. 

Key Product Features

  • Required ECM MOD unlock service is included
  • High-definition, 2.8-inch color screen
  • Easy to use five-button interface
  • Increased memory with faster processor for improved tuning & updating speed
  • Performance tuning for economy, towing, and daily driving
  • Eliminate downshifting when climbing hills speedometer correction for changes in tire size and gear ratio
  • Adjust speed & rev limiters
  • Internet updateable with all-new update software via USB
  • Active/Dynamic fuel management control
  • Vehicle parameter monitoring capabilities
  • Read and clear diagnostic trouble codes
  • Compatible with other performance upgrades
  • Custom expedited service to ensure the ECM back to you before the next workday

Predator 2 GM Release

If you’re looking for more out of your 2019-2020 GM truck, whether it be more power, better drivability, or fuel economy, be sure to check out the DiabloSport Predator 2. You can learn more about this product and others at Diablosport.com.

Article Sources

About the author

James Elkins

Born into a household of motorsport lovers, James learned that wrenching takes priority over broken skin and damaged nerves. Passions include fixing previous owners’ mistakes, writing, and driving.
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