Trans Tune Specifications
 Eliminates 2-1 downshift hesitation at low speed tip-in maneuvers (i.e. rolling stop sign re-acceleration)
• Upshifts earlier in all conditions for improved fuel economy.
• Downshift criteria revamped to best utilize engine torque curve and stay in each gear longer.
• Hill mode optimization to prevent gear hunting
• Refinement on shift scheduling in altitude to provide better engine responsiveness
• Revamped warm-up mode scheduling to provide faster engine warmup (i.e. 1-2 gears lower compared to normal shift maps)
• Increased minimum engine speed after upshift during DPF regeneration for better regen efficiency (this feature will only appear with the GDE Hot Tune installed in ECM).
• Eliminated shift schedule offset based on steering wheel angle to give better continuity of powertrain presence.
• All new tow/haul mode scheduling for maintaining best engine speed range during trailering.
• More use of converter lockup and reduced slip rates to reduce tranny fluid heat load and improve fuel economy.
• More linear response in shifting in medium/high load.
• The shift speeds are quicker and torque response optimized.
• Positive torque requests enabled during downshifts at lower engine speeds for smoother and quicker shifts.
• Highway passing downshifts are sharper and torque is immediate.
• Holds gear better while towing and less hunting on grades.
• Enables 2nd gear launch from a stop using steering wheel paddles (Jeep).
• Jeep Eco Mode now remembers the last mode selected instead of defaulting always to Eco Mode (for 2014-2015 vehicles)
• Jeep Eco Mode has a more relaxed accelerator pedal mapping and shift scheduled designed for fuel economy.
Engine Braking Feature
The engine braking feature is a useful add-on for customers that tow often or folks that drive down mountain grades. The feature is active when the following conditions are met: in gears 1-8, engine rpm above 2500 rpm, and foot off the accel pedal. While the engine braking is active the turbo vanes are closed more to create higher back pressure in the exhaust manifold. This makes it harder to push exhaust out and that force acts on the pistons to help slow the vehicle down. This helps to reduce the need for vehicle brakes and reduces wear on the brake hardware.
The feature not active in normal driving conditions.
Regen Message Feature
The regen message feature will notify of an active regen event in the cluster with ‘regen active, continue driving’. It will also notify ‘regen complete’ when the cycle has finished.
This is a very useful feature for vehicles doing a lot of short trips to drive a bit longer when the regen needs to happen to prevent DPF plugging issues in the field. It is also a cool message to see and better understand what the vehicle is doing.
Trans Race Mode
All Jeep Grand Cherokee
- Engine and transmission warmed up (engine > 80°C, trans > 60°C)
- Vehicle at stand-still, steering wheel straight
- Engage SPORT mode (2014-2015 pull back on shifter once when in “D”, 2016 press button on dash)
- Press brake pedal as hard as possible
- Accelerate engine to more than 1700rpm
- Release brake pedal and apply accelerator to WOT as fast as possible
At the conclusion of step 6, RACE mode is engaged and so shifts are with faster times than normal and *no torque management*.
RACE mode will exit when any of the below are fulfilled:
- Accelerator is released less than 92%, OR
- Current engaged gear reaches 6th or higher, OR
- A drive mode change occurs (i.e. exit manual shift mode, turn on tow/haul), OR
- Steering wheel is turned
After a successful RACE mode engagement, the function is blocked for 45 seconds. This allows all the shift elements to cool down from the prior use.
Trans Dyno Cal
This option is a separate trans tune that holds 5th or 6th gear to allow a full pull on a chassis dyno without the trans downshifting or disengaging lock-up.
88 C Thermostat
This thermostat starts opening at 88 C (190 F) and fully open at 98 C (208 F). This will drop warm operating temps for coolant and engine oil about 10 C (18 F). This is also beneficial for towing long grades as full cooling is reached at lower temps, so it takes longer to reach overheat protection in extreme environments (100 F towing large loads up a 6% grade) like Davis Dam in Arizona.
Only logged in customers who have purchased this product may leave a review.
swaitman (verified owner) –
Just completed the Ecodiesel tune on my 2015 Jeep Grand Cherokee. After the FCA recall re flash, my Jeep had horrible performance and fuel mileage. After the GDE tune, it is better than new- much better. No turbo lag, great MPG, perfect shifting and lots of horsepower. I highly recommend this product- it makes driving fun again and you know the engine will last longer.
David Simmons (verified owner) –
So far so good. Easy Install Process as long as you are familiar with a Windows PC to upload the stock files and download the GDE tuned files to the provided tuner that plugs into the OBD port on the Jeep. I have an older 2014 Jeep Grand Cherokee EcoDiesel so I did not have to install any OBD port jumper. So far I have noticed at least a 3MPG improvement in the city and even more than that on the highway. Regens seem to be not as frequent which is very nice indeed and I hope for longer engine and emissions components lifespan. Power, gear shifts and overall performance improvements across the board have me very pleased so far. I have not towed anything since I installed this but I expect it will show improvements.
James Heath (verified owner) –
I have both the 2014 JGC and 2016 Ram 1500 with Ecodiesel motors. I had both of the vehicles updated to the “NEW” FCA re-tune. There was a noticeable change in performance for both. However it was slightly less for the JGC. I purchased and install the GDE tune on both vehicles. I noticed a significant improvement in performance and fuel economy with the Ram 1500, but have not experienced the same with the JGC tune. There has been improvement in fuel economy but the performance is about the same. Therefore, only 3 stars for the JGC tune from GDE. I received the Engine/Trans Tune Combo WK2 Hot Tune with Regen Message, and Engine Braking. Same for the Ram 1500.
Charles Bidwill (verified owner) –
We have had the tune for about 2 weeks and so far it has been great. By now it is pretty obvious that the EcoDiesel is just awful to drive after the recent flashes from the FCA. The process is very straight forward and if you have ever installed a tune on another vehicle will be super simple and if not just take your time and should be straight forward.
The biggest change for me was the overall drivability. The power is great and makes a huge difference, but when you add that to the overall tune it changes the vehicle completely. The turbo lag is gone and the trans will hold the gears much better with super fast shifts. I have not been paying attention to the MPG honestly since I am enjoying the vehicle so much again. I will pay attention once we hit the highway for an extended period of time. If your on the fence about it just do it there will be no regrets. The tune saved us from selling the jeep!
pgsparks (verified owner) –
I use my GC to tow a 6500 pound camper through Utah’s mountains. I was disappointed with FCA’s factory tune so I searched for a better option. Some guys in my military unit had the on their Ram eco diesel and recommended it. I was skeptical at first but the improvements in towing and the dead pedal pretty much being gone is worth every penny! Don’t wait another second. You will not be disappointed.
boboroach@me.com (verified owner) –
I have a 2015 Jeep Grand Cherokee Diesel. This is the most amazing transformation of an engine I have ever seen. The engine and transmission work together like they did before the FCA butchery of the engine code. Well worth the money and I had no issues with the install. My milage went up from 19.00 to 23.00mpg. Towing is amazing, I have my original Jeep back and far better than it was new. Thank you Green Diesel.
manxboy49 (verified owner) –
Just added the GDE Hot Tune to my 2015 Jeep Grand Cherokee, WOW,WOW,WOW, its like a whole new Jeep……. it drives like a new Engine and transmission were dropped into it, no lag when pulling away, proper shifting sequence in the transmission, no fast shift up to higher gears when in town that caused the engine to labour, if you have a Jeep GC and are just considering it…… DO IT, it’s relatively easy to do the install, the directions are easy to follow, the cost is well worth that new car feel. Thanks for a great product.
2015Jeep (verified owner) –
I cannot say enough about this tune and these guys. We loved our Grand Cherokee when we first purchased it and for the first several years. It provided great mileage and towed our boat superbly. And then the EPA retune came. We said we did not want it, but the dealer falsely convinced my wife when it was in for a minor service issue that our warranty would be voided if we did not do it, so it was done. Ugh!! Huge mistake!! I’m still mad at that dealer. We then had nothing but problems and have gone through 2 turbos as a result. All under warranty, but it had my wife’s car in the shop on average every other month. On our last repair that included a new turbo we were ready to kick it to the curb and purchase a new Defender 110 because it was the most like vehicle we could find. But then I asked around at my local shops and found Green Diesel. I figured one last shot for only about $1,300 was worth the risk as opposed to tens of thousands for a new vehicle. I am so glad I did it. Our vehicle is now better than new. I have put at least 3000 miles on it since the tune, have towed with it, and have gone through several regens. All has gone flawlessly. It has more power, substantially less turbo lag, and I’m getting about 4 miles to the gallon better economy than I was getting with the “EPA” tune. What a tremendous product! If you’re considering ditching your eco diesel for something else, this is well worth the money, you’ll enjoy your vehicle again, and you’ll be reminded why you bought it in the first place.
JAYSON COLE (verified owner) –
I have a 2016 Jeep Grand Cherokee High Altitude. I was very unhappy with the outright dangerous turbo lag, overall drivability, and performance by the revised FCA tune after the EPA recall. So, after researching what was available at the time, I purchased the GDE EPA Compliant Engine/Trans Tune Combo in July 2021 with the Engine Braking and Trans Race mode add-ons. Overall, I’m very happy with the tune. Especially since there is no noticeable turbo lag. The drivability is 10x better and makes the Jeep a lot more enjoyable to drive. I just returned from my first long road trip since getting my tune. I also just returned from a round trip to FL and back with some local driving in FL. I traveled 2,758 miles and averaged 27.3 mpg driving anywhere between 75-85 mph on the majority of the trip. This is at a minimum a 2-3 mpg improvement compared to factory. I’m positive if I drove the speed limit, I would have probably averaged 29-30+ mpg on the trip. If you’re looking for an EPA compliant tune, I would say you’d be happy with GDE. They have great customer service as well.
James Hendricks (verified owner) –
2014 Jeep Grand Cherokee Ecodiesel with ‘GDE – Engine/Trans Tune Combo’ – Even the recent FCA tunes are still horrible, mileage is decreased, extended mileage between DPF regen, drivability is horrible (like driving a boat and drifting though intersections).
I can validate all the previous reviews stating that the GDE flash makes substantial improvements to the operation and drivability of my vehicle. Regular and DPF regens, approximately 5 mpg increase, and great throttle response (drivability).
Additionally, the support team at GDE is quite responsive and even helped me understand some error codes that pointed to a DEF pump failure on my vehicle.
Truly above and beyond support!
I highly recommend this product.