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Messages posted by: GreenDieselEngineering
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Our newest tune offering focuses on improving the Grand Cherokee CRD fuel economy and part/full throttle performance.

The average fuel economy gain is roughly 3-5mpg depending on driving style and average speed. This is accomplished by optimizing the fuel combustion through changes in injection timing, fuel pressure, boost pressure, pilot injection events. EGR issues are eliminated and the smoke emissions are reduced substantially. For vehicles equipped with a DPF (particulate filter), the regeneration frequency is less and backpressure tends to be lower further improving the fuel economy. In normal driving the exhaust temps are 50-100 F lower than stock to improve engine and turbo life.

Off the line performance is improved through improved combustion and an optimized turbo vane position. The 0-60 mph results show the GDE tune to be about 1 second faster than stock. This equates to about a 40hp gain at 4000rpm. Torque is increased from 1800-4000rpm linearly by about 40 ft*lb.

This tune can cause sensory overload when the go pedal is hammered! The fuel economy improvement is icing on the cake, especially considering the high price of diesel fuel.
Below is a link showing the GDE Fuel Economy Trans Tune shift schedule.


Here is a link showing the GDE Towing Trans Tune shift schedule.


The primary difference is the towing tune will hold 4th gear until 70mph (2280 engine rpm) and then upshift to 5th gear. Using 4th gear between 50-70mph while towing loads over 2500lb. is beneficial for holding gear while traversing hills and it also keeps the engine rpm in the most efficient torque zone to reduce the tendency for gear hunting.

In extreme towing conditions it is still recommended to turn off the O/D and tow in 3rd gear. This will keep the engine rpm higher to maximize coolant flow through the radiator and spinning the mechanical fan faster to increase the air flow across the radiator.
Unfortunately, we are out of belts at the moment. Not sure about getting more in. The part numbers for timing belt replacement ar as follows:

Timing belt 5142579AA
Idler pulley 5142573AA (2 required)
Tensioner 5142798AA

Good luck with the upcoming job!
There is a transmission issue. Most likely the torque converter is on the way out, but it could also be a fluid contamination issue or something the valve body. Have you noticed any strange shifting behavior prior to the code?

Send me an email and we can discuss. When you open PWGConsole you can change the language to English with one of the menu buttons. Since the tool only holds 3 tunes, I am not aware of how to delete the uploaded tunes without requiring flashing the CRD back to stock, then erasing the tool. I beleive we will need a new original file read. Thanks.
A variable idle speed based on cruise control is not possible on the KJ CRD application. The logic you are referring to is a variant of an all-speed governor unit. To do this on the CRD would require new logic inside the engine controller and massive investment from Bosch to write the code.
Chrysler recently released metallic glow plugs and a corresponding glow control unit (smart relay) to replace the ceramic glow plugs currently in the KJ CRD for 2005 and 2006. The part numbers are as follows:

Kit (4x GLP + 1x GCU): CY P/N 68090434AA

GLP: CY P/N 68090430AA

GCU: CY P/N 68090431AA

It is very important to update the engine PCM tune prior to connecting the new glow plugs. If not, the metallic plugs will be supplied with too much current and overheat. GDE has updated tunes available for any customer wishing to coordinate the hardware and software change together. The other option is to have the dealer flash the PCM with an updated stock tune. Then we can work out the details of having the GDE tune reinstalled using our flash tool loaner program.

The flash tool loaner program will have a $50 fee to cover shipping costs and tune coding.
The CRD is prone to lose around 10% of its fuel efficiency during winter months. This is partly due to winter fuel having less BTUs than the summer blends, however it is also related to the much cooler air entering the engine and lower coolant temps.

Options to reduce loss in fuel efficiency:

1. Remove the accordian style air inlet snorkel at the front of the air cleaner. This will allow the engine to ingest warmer engine compartment air through the air filter and tends to improve FE.

2. Remove mechanical fan during winter months (if not planning to tow a trailer). This will tend to reduce air flow through the radiator and reduce engine load at the same time.

3. Block a portion of the front of the radiator to reduce the amount of cold fresh air that naturally flow through it. This can have the largest impact and may need some fine tuning in regards to percentage blocked vs. temperature on the coolant gauage. Blocking 50% of the radiator surface is a good starting point.

With the GDE tunes the engine tends to run slightly cooler as less fuel is required to achieve the necessary torque while driving or idling. On our vehicles the coolant temps tend to run around 170-180 F, right around thermostat start of opening with a bias towards 170 F during winter months. You can remove the according snorkel on the front of the air box to allow warmer engine compartment air to get pulled through the air filter. As it gets even colder, we will most likely remove the mechanical fan for the winter or just block a portion of the radiator from the fresh air stream.

Also, keep in mind we lowered the threshold to turn off the viscous heater while the engine is warming up. Oringinally the VH would remain on until the coolant temps went above 161 F and would turn back on if the temps dipped below 150 F. With the tune, the VH will turn off during warmup when coolant reaches 131 F and turn back on when temps dip below 122 F.
The flash tool is $300 and the engine tunes are $450. Our tunes already fix the EGR issue and do much more to improve drivability and fuel economy. We looked into a manual conversion, but at the very low volumes it is not a worthwhile venture due to the design cost of a single mass flywheel and unique adapter plate.
In the end it is a wash, just the core deposit to ensure we get the stock TCM back for the next customer. The TCMs are not tied to the vehicle with VIN or any sort of security.
We can tune the KJ engine ECU to work on a TJ application. The options include setting it up for a manual trans or using the 545RFE automatic trans. With either option we would need to work out some details to properly obtain the vehicle speed information. This is sent via the CAN bus on the KJ and most likely will require some work unless the wheel speed sensors from the KJ are carried over on the TJ. It would be best if you can find a wrecked KJ to swap parts from as this would substantially reduce your costs.
As of 24 Sep 2010, we received a fix from Alientech that now allows the flash tool to link and communicate with Windows 7. Please email us if running Windows 7, the fix must be installed prior to running the software the first time.
The flash tool will not work with the trans tune as the protocol is different. The trans tune is best suited for a TCM exchange to keep the CRD on the road except when swapping out the controller.
It should be roughly the same procedure as the right side mount, however, the lower nut might require a little more finess to gain access to and loosen. Good Luck!
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