Ask our Experts, we're here to help!
GM’s L5P Duramax is one of the best diesel engines GM has designed. Debuting in 2017, the 6.6l has the grunt you need with 910 lb-ft of torque, with 90% of that power coming in at 1550 rpm, the L5P gets the job done. That doesn’t mean that we diesel drivers don’t want more. You could take your truck to diesel shop and have stuff upgraded and boosted and spend thousands upon on thousands doing it, OR you could slap on a piggy-back ECM module and get what you are looking for, like better fuel economy unloaded, better power and torque when you need it, and silly power when you want to show off. The Edge Pulsar V3 has all of that.
Our demo truck is a 2018 Chevrolet 2500HD Z71 crew-cab truck with 95k miles on it, which for a diesel, is just starting to get broke in. We have owned the truck for about a year and put it through the ringer. It hauls heavy loads regularly, gets lots of highway and in-town miles, and basically gets used the way a ¾-ton should get used as a shop/ranch truck. The fuel economy as stock has not been atrocious. According to the truck's on-board computer, around town it gets an average of 13-14 MPG, while on the highway an average of 17-18 is seen in most cases while running at highway speeds (75-80 MPH in Oklahoma and Texas). However, with diesel prices reaching nearly $2 more than gas these days, every visit to the pump hurts.
Before any work is done, the grounds for BOTH batteries were disconnected. Failing to do so can cause damage.
Having traded in a 2019 Chevy High Country 1500 with the 420hp 6.2L gas engine and a 0-60 of 5.4 seconds, the performance side of the diesel truck lags behind in a big way. Don’t get us wrong, over 900 lb-ft of torque is awesome, but that 8.2 second 0-60 is a little lacking in the “show-off” department. We wanted to get some of that performance back. Moreover, with a diesel, there are some other areas that you really want to have more control over, such as the regen system. Case in point, our truck kept popping up with a warning that the system needed to do a regen, so we needed to keep driving. That isn’t always possible and it kept repeating this for several days, even though we had driven several hundred miles. With the Pulsar V3, we have the option to force a regen in either manual mode or service mode. Service regen requires the vehicle be stopped, but in this case, we were driving on the highway, so we did a manual regen, within 20 minutes, the regen was over and we didn’t even notice that is had gone through the cycle. The truck also has a CTS3 display unit, so we could see the EGTs to know when it was in the cycle.
The Edge Pulsar V3 gives you the ability to adjust most of the necessary parameters, like wheel/tire size, high idle adjustment, shift backdown, data logging, speed limiter, etc. It also gives you five power levels to choose from, which is good as most buyers are after performance tuning. These are all shift-on-the-fly tunes, and can be accessed two ways. The first is through the cruise control buttons. When the cruise icon is off, the power levels can be adjusted by tapping the + or – buttons. The speedometer displays the power level: when it reads 0, this is the stock tune. 10 mph is level 1, which is the economy tune, 20 is level 2 “light tow” which adds 58 horsepower and 125 lb-ft of torque, level 3 is for “heavy towing” and adds 78 horsepower and 175 lb-ft, level 4 is the performance tune which adds 103 horsepower and 234 lb-ft, and level 5 is the “Extreme” tune that adds 132 horsepower and 293 lb-ft. You may say “well I’ll just run level 5 all the time then!” and you can, but your fuel economy will tank.
The ECM is located next to the driver side battery. Each terminal was cleaned with some electrical contact cleaner to remove any dirt or grit that may cause issues with operating the lever.
Installation of the V3 is really simple, but it is not “easy”, particularly on 2017-2018 trucks. What makes it difficult is that GM left almost no extra length on the middle connector, so you have to try and operate the connector, which is a lever-action cammed plug, with the ECM in place. The power steering pump reservoir and return line are right in the way and there is about ¼” space between them, so you will get frustrated with that one plug. At least the other two plugs are super easy to remove and re-install. The other issue with the install is that these plugs are very brittle, specifically the slides inside them. In a diesel, where the underhood temperatures can be really high, they just get brittle and break often. Edge is aware of this and carries a cam replacement kit (p/n 98108) for customers who break them. Take our advice: BUY THIS WHEN YOU ORDER THE V3 SYSTEM. The kit is about $40, but you won’t have to wait to finish your install like we did when ours broke. Before you remove the plugs, and before you install them onto the ECM, spray them down. We used electronics cleaner, which is safe for all terminals and electronics. After the cam broke, we applied some dry lubricant to the terminal mechanisms to help prevent this from being an issue in the future. Our middle terminal also broke the retainer tab for the lever, which is replaceable, but we have yet to find one for sale anywhere. We glued ours together with high-quality super glue. The cam does all the hard work, the lever just moves the cams.
Each lever has a red locking tab. Use a small screwdriver to slide the lock back. These are really good at peeling off fingernails, so use a tool. Start with the smallest terminal first, the one closest to the radiator. Press down on the tab and slowly lift the lever. You will likely feel some resistance. In order to not break the cams, rock the lever back and forth while applying very light pressure on the plug. Once it moves freely, raise the lever and the terminal will push off of the block. Next, remove the 10mm bolt on the upper front corner of the ECU. This bolt should be kept for reuse when the V3 unit is NOT installed, such as trips to the dealer. Now the ECM can be lifted up and away from the power steering pump and the other two terminals removed.
Other than the issues with factory junk plastic, the Pulsar V3 is a 5-minute install. The Pulsar V3 is a piggy-back module, so it doesn’t actually modify the factory ECM, which is great because you can just take it out if you need to visit the dealer for anything, avoiding any warranty issues. The factory ECM comes out, the V3 piggy-back module is pressed onto the top 2 terminals and is locked into place with a pair of brackets, then everything is reinstalled into the truck with all three factory terminals connected, and that is it. It can be done in about 5-10 minutes. The results? Well worth it.
This is one of the broken slides. They slide out of the terminal, and are easily replaced.
On our truck, we installed the unit and immediately drive 1,200 miles one-way to put it through its paces. We did our fuel economy tests at level 1, and compared that with the stock tune BEFORE installing the V3 module. Results will vary based on your driving style, terrain and weather conditions. In our tests, we drove the truck in 30-mile segments of similar conditions, recording the average economy at three speeds: 65 mph (which is difficult on most interstates these days), 75, 80, and our average in-town driving. Having driven the truck for a year, we already knew what the truck was capable of with our driving. According to the truck's on-board computer, our in-town average was 12-14 mpg on average, which is OK, but not great. On the interstate, the truck saw the largest MPG increase at 65 MPH, reading 24 mpg, 19-20 MPG at 75, and 16-17 MPG at 80. While the on-board computer isn't necessarily the most accurate MPG reader, without a doubt these are impressive mileage gains.
The Pulsar unit is a piggy-back, so it mounts to the ECM. On the back of the V3 module are two terminal blocks that match up to the ECM. The module was placed on top of the ECM on the bench and were carefully aligned, then the module is pressed down to seat the terminals into place. We mounted the supplied brackets to the V3 module. The small bracket goes onto the bottom of the ECM. The upper bracket is also the mounting tab for the assembly. Note that we marked the top of the ECM so we didn't install the brackets upside-down. Installation is the reverse of removal. The large rear-most terminal goes on first, with the ECM above the battery, then the assembly is lowered into position and the middle terminal is mounted. You can see just how tight of a fit this is. You must take great care to ensure the wire harness does not get wedged between the ECM and the pump or brackets, as you can break the mounting tabs for the module. Note that the power steering reservoir cap has been removed for added clearance...don't forget to re-install it! The small terminal goes directly back onto the ECM itself. The kit comes with a set of nuts and bolts to secure the assembly to the ECM platform. The hard part is now over.
With the V3 in economy mode, things changed really fast. At 65, the results were astounding, as the truck said that it was knocking down 33.8 mpg, yielding over 850 miles per tank. If you are driving on a state highway or an interstate where the speed limit is 65-70, you can get this kind of economy with ease. However, this truck spends most of its time in Oklahoma and Texas, where the interstates are 75+. At this speed, the 2500 HD Duramax was claiming between 24 and 29 mpg. The variance here is due to weather and terrain conditions. At 80 mph, the economy dropped a fair amount to 19-22 MPG in most areas. There were some stretches of road where there were lots of hills that hurt our economy across all speeds. It is the overall gains that we are most impressed with, and at 65 mph, getting nearly 34 mpg is incredibly impressive.
If you do not have the Insight CTS3 display, then you use the cruise control buttons to access the programming. Holding the cruise cancel button initiates the process. The cruise light cannot be lit on the dash, otherwise it won't go into program mode. When the speedometer swings to 140 MPH and back to zero, you are in programming mode. The (+) and (-) buttons on the cruise control change your parameters...for example, with the speedometer at 30 MPH, this signifies that you are in Level 3 Performance mode.
0-60 response is greatly increased when driving in the performance tunes at level 4 and 5. We saw a nearly one-second improvement in our 0-60 times at level 5, going from 8.2 seconds in stock form to 7.5 at level 5. The Extreme tune (level 5) is raucous, to say the least. The throttle response is immediate, the truck launches down the road and gets up to speed very quickly. We have not run a quarter-mile test yet, but it is much faster that the stock tune. The caveat of level 5 is that we tended to drive much more aggressively with this tune, and we put our foot through the floor most of the time, which meant that we were getting horrible fuel economy and even though it is really good fun, diesel is just too expensive. Level 5 is NOT rolling coal! in fact, we didn’t notice any change in exhaust smoke during any of our test, which is a very good thing.
Before we installed our V3 unit, our truck's in-town fuel mileage was averaging a claimed 12.8. Note the best "before" MPG recording was 24 MPG. In Level 1 (economy mode), we saw a best of 33.6 MPG at 65 MPH, and at 75 MPH, we saw 24.7 MPG average (between 23 and 26 MPG) on our 1,200 test trip.
Overall, this is guaranteed smile-maker addition to your truck. Your wallet will be thankful considering the fuel savings, and you will be grinning ear to ear when you put it in level 4 or 5 for some showin’ off. If you add the Insight CT3 display module like we did, the controls are even easier and you get performance tuning, gauges, and some other really cool features that you will absolutely love. The best thing about the Pulsar V3 is the shift-on-the-fly tunes - you can roll in economy mode and bump it up to any other level in less than 5 seconds to adjust for conditions and terrain, giving you the ultimate control.
To maximize the most out of our V3 install, we paired it with an Insight CTS3 as part of a package deal, with provides a lot of extras for the operator.