How To Install Pulsar LT Onto Your Duramax-Equipped GM Truck

11/09/2022

How To Install Pulsar LT Onto Your Duramax-Equipped GM Truck

11/09/2022

Many diesel truck owners simply want to get in and haul whatever load they have hooked up. That doesn’t mean that you don’t want to have some extended level of control or improved performance on your truck. Adjusting for wheel/tire combo, idle control, DPF regens, and throttle response are commonly desired controls that most diesel truck owners want. With the Edge Pulsar LT, you get all that and more without voiding the factory warranty.


Unlike a complete module conversion like the Pulsar V3, the Pulsar LT unit does not affect the ECM at all. The LT does not offer the same performance gains as its older sibling, the V3, but you can definitely regain lost performance from wheel/tire changes or gearing upgrades. Here is the full breakdown of what the Pulsar LT is capable of:

Calibrate Tire Size (29" - 50.9") - If you swap wheels and tires on your truck, the ECM will not get the correct information from the wheel sensors. This causes incorrect speedometer readings, which can certainly result in tickets. It will also throw off your fuel economy. Recalibrating your truck to adjust for the correct tire diameter fixes this.


Modify Gear Ratio (2.00 - 6.99) - If you change your gearing ratios in your differential, you need to let the ECM know, similar to the tire size calibration. The Pulsar LT allows you to do this with ease.


Transmission Relearn - The 2017-up Duramax trucks has a learning transmission. If your ECM has been tuned, then your transmission may act a little funky. The Pulsar LT has the ability to force the TCM (transmission control module) to relearn your driving style. This can also be really helpful on used trucks that may have been driven “aggressively” and shift much harder than you prefer, or vice versa.


Clear Diagnostic Trouble Codes - You can quickly clear any trouble codes on the fly by simply using the cruise control buttons, you can do this while driving without connecting a scanner tool. This just clears the codes, it does not display the actual code information.


High Idle 700-1100 RPM - If you have reason to leave your truck running at idle for long periods, you need to bump the idle up to increase the oil pressure and maintain engine temp. Leaving a newer DPF-equipped diesel idling for long periods at low idle generates a lot of extra soot, which clogs up the DPF filter as well as causing wet stacking. Wet stacking happens when all the fuel injected into the combustion chamber is not properly atomized due to lower temperatures. This leads to unburned fuel in the chamber that washes down the cylinders, increasing engine wear. The Pulsar LT gives you the ability to bump up the idle, from 700 RPM to as high as 1500 RPM to reduce engine damage and DPF clogging during extended idling. There are a lot of reasons that a diesel driver may need to leave the engine running, even though it is not good for the engine. Raising the idle helps alleviate those issues.

Reprogram TPMS Threshold (40 - 99 PSI) - Heavy trucks typically run higher tire pressures than half-ton trucks, most ¾-ton and 1-tons run 70-80 psi tires, some even stagger the pressures such as 50 in front and 80 in the rear. Atmospheric changes in the environment can alter your tire pressures, especially after being parked long enough to fully cool the air in the tires. You can adjust your minimum and maximum tire pressures through the Pulsar LT, so that your vehicle will warn you when your tires reach the minimum or maximum range. This is very valuable for trucks that see maximum payload regularly or in areas where temps swings are common.


Manual DPF Regen - This is a big one for modern diesel owners; the ability to force a manual regen cycle can be the difference between a well-running truck and a service call. If you live or operate in an area where you do a lot of stop and go driving or idling, your engine will not reach the operating range for a standard regen, and your DPF will clog up. Most service centers charge 300-700 to do a manual regen on a diesel engine, just one manual regen pays for the Pulsar LT unit.


Speed limiter - The factory puts a speed limiter on these trucks for two reasons- safety and safety. The problem is that they are bit too conservative for today’s speed limits. Most highways in the US have 70-75 MPH speed limits, and some areas are 80-85. Passing slower moving traffic can quickly have you passing 100 mph for brief moments, and the occasional emergency situation where speeding is required, bouncing off that 98 MPH limiter can actually put you in more danger. The Pulsar LT allows you to adjust the limiter up to 140 MPH, you can take it down some too if necessary. BEWARE: The driveshaft on 2017-up GM trucks is the main limiting factor for high speed driving. Because they are so long, they reach critical rotational speed faster, which causes them to literally bend like a wave. If you increase your speed limiter, be realistic and prudent. DO NOT raise your limit above 115 without an aftermarket driveshaft that can handle the higher speeds.


Adjust Throttle Response - for most drivers, this is the one feature you will use the most. Drive-by-wire pedals leave a lot to be desired in the realm of throttle response, and diesel trucks take a little longer to rev up than a gas engine in the first place, so the factory throttle response is pretty poor. With just a quick touch of the cruise buttons, you can adjust the throttle response on the fly.


The Pulsar LT has 6 levels of throttle response, from stock to 65% boosted. All of the modes for the unit use the speedometer to access the desired point, so every 10-mph on the dial is a new setting or mode. For the throttle response, the levels are as follows:


0: Stock

10: REDUCE response, 15% less than stock

20: INCREASED response, 15% more than stock

30: INCREASED response, 30% more than stock

40: INCREASED response, 48% more than stock

50: INCREASED response, 65% more than stock


Yes, you read that right, you can lower your throttle response. This mode is perfect for reversing to connect a trailer without accidentally moving too fast, or when you are operating on slippery terrain, such as sand, gravel, rock crawling, etc. If you have your truck at level 5 on a gravel road, it will just dig a hole. This is the main performance benefits of the Pulsar LT. Our test truck, a 2018 Chevrolet 2500 LT Duramax, we tested 0-60 times before and after. In stock form, the truck ran a very consistent 8.05 second 0-60 time. When the truck was set at level 5, that 0-60 was reduce by nearly a full second, to 7.22.

There is a secondary performance increase that you may find with the throttle response changes, as you may see a slight increase in fuel economy at the lower level settings. This is mostly due to not having to put your foot to the floor as often to get a bigger engine response, but your results may vary.


Installing the Pulsar LT is ridiculously easy. The module comes with everything you need to install and mount the unit under the hood. Because it uses the cruise control buttons for operation, there are no wires to run into the cab. Simply disconnect a factory plug next to the under-hood fuse box (driver-side battery), connect the supplied piggy-back harness between the factory plug, and connect the pulsar LT module to the piggy-back harness. The kit comes with a piece of Velcro to attach the module to the top of the fuse box and some zip ties to secure the harness. This takes about 2-3 minutes. You do need to disconnect the grounds from both batteries. If you do not do this, the module will not be recognized by the truck and you will have to do it anyway.

Accessing the modes in the module is very simple. With the vehicle not running, turn the key to the run position (push-to-start vehicles need a 5-second pulse touch WITHOUT touching the brake pedal to activate the vehicle but not start). If your truck has digital gauges, bring up the digital speedometer, though the analog speedo operates as well. Hold the Cruise Cancel button until the speedo sweeps to 140 and back to 0. Then the +Res and -Set buttons will move the speedo dial to the desired speed (in 10 MPH increments). Press the Cancel button to select that mode, then use the +Res and -Set buttons to select the settings in each mode you are operating. The kit comes with a nice quick-reference guide that you can keep in your truck for get this, “quick reference”, what a handy little feature.


The throttle response mode is active when the cruise control is not being used, so anytime the cruise control light is NOT activated, pressing the +Res or -Set button will raise or lower the throttle response setting, so keep this in mind as you may accidentally adjust it. Other drivers of your vehicle should be aware of this as well. The other option is to just ensure that the cruise mode is always on to eliminate accidental changes. The cruise control operation is not affected by any of these changes and will remain fully operational.


Edge Products does recommend removing the module any time you have to take the truck to a dealer for service just to ensure that any ECM modifications done at the dealer are not affected by the Pulsar LT module. This unit does not void the warranty, but it is always best to err on the side of caution when it comes to dealership service.

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