Whether you’re buying a complete vehicle or just an engine, it’s important to know what you need from the donor vehicle in order to operate the engine or complete drivetrain.
What do I need to get from my donor?
A list of everything you will need in order for the drivetrain to operate.
For nearly all Duramax drivetrains there are a few basic items that are common and will be needed for all donors. It’s best to try and get all of this from the donor vehicle if you have it available or if you are purchasing a used drivetrain, be sure to ask them to include these items in the price if possible.
ECM
TCM
Upper Engine Harness
ECM/TCM harness
Accelerator pedal
Mass Airflow Sensor (MAF)
Accelerator pedal extension harness (2001-2007)
* There are a few different versions of accelerator pedal extension harness on early models, and we also have options for changing pedals on some versions so email us if you have questions or don’t have your original pedal extension harness.
What do I need to send to Dmax Swap?
A list of the components that we will need from you in order to get you set up for standalone operation.
Please read completely.
ECM
TCM
ECM/TCM harness
It is important that you take some time to clean the harness and control modules to the best of your ability to avoid extra fees for cleaning, super dirty, or oily control, modules or harnesses.
In order for us to build and program the appropriate calibration for your engine control, module and transmission control module you will need to ship both of the modules in careful packaging to the appropriate address in ordering guide.
Be sure to watch our YouTube video at the end of the ordering guide to help understand which portion of the harness we need. Make sure you don’t leave any extra unnecessary wiring in your shipment as that will add additional shipping costs when returning your components.
You will also box up your ECM/TCM harness and ship it to the appropriate address in the ordering guide. These parts are expensive and many of them are no longer produced by GM so take some care and packaging your parts to prevent costly damage.
If you have any questions about your donor or any of its components, feel free to email us.
The Duramax 6.6 turbo diesel was offered in Chevy and GMC van applications in the following configurations:
LBZ/4L85e
LMM/4L85e
LMM/6L90e
LML(LGH)/6l90e
The Duramax used in Van application is significantly de-tuned far below the pick up truck power levels due to the transmission being significantly limited on torque capability. These engines are all tuned to a maximum of 300hp and the operating systems used for the engine/transmission control are specifically designed for shuttle bus style, torque delivery and shift quality. The important limitation is the maximum torque capability of the transmission and the Duramax engine easily produces 800 foot pounds of torque with only slightly improved permanence tuning which is far beyond the torque handling capability of the 4L85 and 6L90 transmissions. This is why the torque management is so extreme on up shifts to protect the transmission, but it is also why the shift quality is very poor and there is harsh Defuel on up shifts.
The LMM Duramax, produces:
660 lb-ft of torque with an Allison 1000 and OEM pickup truck calibration
Only 460 ft-lbs max torque capacity with a 4L85e
Only 531 ft-lbs max torque capacity 6L90e
Harnesses we do not support:
– OEM LBZ/4l85e with T42 TCM van harnesses – OEM LMM/4l85e with T42 TCM van harnesses – OEM LMM/6l90e van harnesses. * All of these can be converted to “Engine Only” for use with 4l85e and US Shift standalone trans control or switched to Allison 6 speed.
In all of these applications our strongest recommendation is to ditch the 4L85 or 6L90 transmission and convert to an Allison six speed. We can utilize your van harness and convert it to accept a six speed Allison transmission control system. You will have to purchase a different transmission control module to work with the 6 speed Allison.
We can support the 4L85 transmission as an “Engine Only” standalone harness to run behind any Duramax engine and utilize a US shift standalone transmission control system for the 4L85e so you can get maximum performance and ideal shift quality, especially when modifying the 4L85 transmission to handle more than 500ft-lbs of torque with mods like 300m input shaft and other internal upgrades..
For the LMM/6L90e the only option is to switch to either the Allison 6 speed or 4L85e. We do not support the 6L90e behind any LMM Duramax.
For the LGH/6L90e we also recommend converting to the six speed Allison but we can support the 6L90 although it will only be programmed with stock power level.
We know you prefer to talk on the phone rather than typing…BUT
At Dmax Swap we get a lot of technical questions, and that’s great because we have the answers when it comes to Duramax conversions; We have put a Duramax in everything but an airplane!!! We have been tuning with EFILive and building high performance Duramax powered vehicles since 2002, so there is nothing we can’t help you with. We have you covered from complete engine and transmission builds to custom calibrations for any application.
We always contact customers, that have purchased tuning from us, prior to programming their modules. We have each customer follow our ordering guide which walks them through the ordering process, consisting of purchasing products, completing a tune request form so that we can document their build and give us the proper information to make recommendations as well as design the calibrations to work for their build and finally, where to send their donors. We are happy to provide recommendations for components or other performance upgrades and even recommendations for cooling, electrical, and even transmission and transfer case solutions. But we need DATA!
We make email our primary form of communication. This benefits both the customer and us mutually: – Questions are answered and documented. – We have all of the information needed to properly formulate a recommendation or solution. – Both the customer and we have records of what was discussed and delivered. – The communication can be organized with the proper customer information or order number
We don’t provide support for: – Other companies tuning, electrical, or harness products. – Late model integrations. This means we only support vehicles prior to 1998. This doesn’t mean we don’t know how to put an LBZ in 1/2 ton 2003 Chevy Tahoe and make it all work… it’s just not the focus of our business or part of our business model.
We have seen the value of keeping things documented for reference and clarity; It saves significant time and reduces errors. We work off of this model and have written this article to explain it briefly so our visitors/customers can understand the logic. As new common questions arise, we continue to update the FAQ, refine our ordering guide and even create videos, to make the experience as complete and streamlined as we can.
We look forward to hearing from you and helping you save the world… One Duramax at a Time!!!
We often get the request to provide a custom/extended length harness between the engine connections and the control module connections. This is typically requested to accommodate remote mounting of the control modules.
Unfortunately, we do not provide this service for the following reasons:
This would require a significant amount of labor
Due to the large number of solder joints (80+) this introduces many possibilities for failure
Increased wire lengths affect the resistance of circuits and may cause interference to critical signals (cam, crank, injectors, etc).
If you would like to modify the harness yourself, be aware that technical support will only be provided prior to making any modifications to the standalone harness, so it’s highly recommended to run test the harness and engine before making any modifications in case there are any issues with your engine that you may need support with.
Switch on the fly (SOTF) tuning on the LML Duramax platform does not provide 5 individual maps like previous year duramax ECM’s. It simply utilizes the fuel rail temperature to limit the total fuel quantity (MM3). It is the electronic equivalent of putting 4 different sized wood blocks under your accelerator pedal.
Whether tuned with EFILive or EZLYNK, your ECM will only have one calibration. Therefore we don’t offer the SOTF (DSP-5) option for LML since we don’t see the added value and prefer to keep the fuel rail temp functioning as the OEM intended.
We’ve had some people express their intimidation of installing the standalone harness and have questions about how they are to be wired. Each connection is labelled and there are tailored instructions included with each updated Duramax standalone harness. In this video, you will get some great information, tips for installation and a visual demonstration of the process. This example is an LMM Duramax, without the transmission portion, but the installation to the upper engine harness and power source to make the Duramax run is basically the same for all LB7, LLY, LBZ, LMM and LML applications.
We are now offering Duramax LML standalone solutions. Please look under the RPO Codes top level, then LML to see the harness and tuning as well as the LML Y-bridge and more upgrades or the wiring options under shop. Also, we highly recommend all tuning for your harness is done through us and it is very important to get your TCM tuned, as well as your ECM.
Our Dmax Swap standalone tuning for Duramax power trains are performed using EFILive software. We have experience tuning standalone duramax power trains in literally dozens of configurations, engine only configurations from boats to race vehicles as well many applications with factory Allison, 6l80e and 4L80e controllers.
It is important to tune not only the ECM but also the TCM for proper torque management and shift control. GM diesel operating systems are very dependent on torque input and shaft speed to determine shift feel and quality. Therefore everything from vehicle weight, to tire size and gear ratio can affect not only the transmission operation and durability, but also the power delivery from the engine.
We offer ECM and TCM custom programming for your crazy application as follows:
ECM Tuning
Single custom Engine calibration- We connect your ECM on a bench harness and read out the calibration in the provided module and confirm
Communication and retrieve the file installed currently. We choose the most appropriate operating system for your application (this is very critical for operation with any GM factory TCM). The file is then calibrated for your modifications and desired power level. Everything from injection pressure to turbo cane position tables are altered to generate the most efficient operation at the desired power level.
DSP-5 Tuning
Duramax Selectable Programming (DSP-5) provides the ability to load multiple Calibrations in the ECM which can be instantly accessed through a 5 position switch in the vehicle. This can be used to provide multiple power levels in the ECM “on the fly”.
TCM Tuning
Transmission control module calibration, as previously stated its critical to ensure the proper OS match between ECM and TCM, so the module is connected to the bench harness, read out, and the proper OS is selected for calibration. The custom calibration includes adjustment for shift timing, shift speeds and WOT shift speeds/RPMs. Torque management is handled by tables stored into the TCM, which are edited to compliment the ECM calibration.
In order for the 4wd Allison to shift properly, it must receive a Vehicle Speed Sensor (VSS) signal.
This sensor is typically located in the transfer case on a factory equipped Duramax 4×4 truck. It consists of a magnetic pickup that reads the rotational speed of a 40 tooth count reluctor wheel. The TCM needs three values programmed into it in order for it to get an approximate vehicle speed calibration:
1. Final Drive ratio
– High range total ratio from the transmission output shaft to the rear axle
– If the speed sensor is located after the transfer case low range gearing, we must also know the value of that reduction ratio (the 4wd low input wire must receive a signal when in low range to apply this ratio)
2. Speed sensor Reluctor wheel tooth Count (this is typically 40 teeth per revolution and it is recommended that this the value used if you are custom machining the reluctor for your application)
3. Tire Overall Diameter
So its important to know where the speed sensor is located (before or after the Low range of the T-case), and what the gear ratios are.
If the final drive ratio or tire size are slightly off, it will still work fine but the shifts will be slightly higher or lower than the calibrated values. However if there is any difference between the measure shaft speed and the transmission output shaft speed, the TCM will assume the clutches are slipping and put the transmission in Limp mode.
It is typical for many custom builds to locate this in the adapter on the rear of the trans which works great, the only drawback is that the speedometer will not be correct when the vehicle is in Low Range.
The LML engine was only offered in pickup truck configurations in both the 2500 and 3500 models. This 397hp/765lb-ft configuration is only available with the Allison 1000 transmission.
The LGH is a detuned version of the LML engine and was offered in two configurations:
LGH/Allison (cab and chassis trucks and fleet vehicles) These very closely resemble the LML Truck configuration and we do support these drivetrains in conversions.
LGH/6l90 (vans, cutaways, busses) WE DO NOT SUPPORT THIS CONFIGURATION!!!
The LGH / 6L90 configurations were significantly de-rated (260hp/525lb-ft) in order to prevent transmission damage due to the lack of input torque capacity of the 6l90 trans. These powertrain combos are often cheaper and although there are no major internal engine differences from the LML, there are many differences in the intake, wiring, and emissions systems. Many of these LGH specific components are designed with the significantly lower power output in mind, which create significant restrictions when attempting to make power at or above the factory LML output.
For the reasons listed above as well as many others, we do not support the standalone operation of the LGH/6l90 combo. We can provide you with harnesses and modules to run “engine only” as an LML but you will have to change the upper engine harness as well as a few other intake components and potentially relocate some sensors and the glow plug co trip module. Controlling your transmission in this configuration will have to be done by some other standalone system and we do not provide wiring or Tuning support for these systems. However we know it can be done.
We strongly suggest you find a way to make the Allison work in your swap if you intend to utilize the power of the LML Duramax. If you are set on using a smaller transmission, then an earlier 2002-2010 Duramax powertrain with either a 4l80 or 6l90 is a better choice.
We could spends a lot of time explaining why the Allison is the right choice behind the Duramax, but we prefer you just trust the experts since we have an extensive amount of experience with these engines and transmissions and we can guarantee that whatever you are thinking…we have already tried it! Our goal is to ensure that your money is well spent and that you swap provides reliable performance for years to come.
Whether it’s a diesel powered race vehicle or simply a show and tow rig, let our experience help you make the right choices to save you money in the long run and ensure that you exceed your project goals!
The L5p was first introduced in 2017 and continued until 2019 with the 6 speed Allison option. The best way to identify this engine is the large turbo actuator on top of the VGT turbo as well as the large intake plenum that forms a “Y” connecting to each cylinder head individually. They also have a large SCR catalyst attached directly to the back of the turbine housing.
Direct injection, high-pressure common rail, Denso HP4 pump, Denso GS4 Gen-III solenoid fuel injectors
Horsepower
445 hp @ 2,800 rpm
Torque
910 lb-ft @ 1,600 rpm
2011 – 2014 Duramax LML
Quick Identifier:
LMLs were used from 2011-2016. Ways to identify this engine: – Orange wire loom on electrical harness due to high voltage – Dual EGR coolers
The LML Duramax is released for 2011 model General Motors & Chevrolet HD trucks. The latest version of the 6.6L Duramax, the LML uses advanced emissions equipment, including the use of diesel exhaust fluid injection, to reduce nitrogen oxide emission levels by 63 percent over LMM powered trucks. This allows the LML to exceed currently mandated federal emissions requirements & meet future future requirements as well. Not only is the LML the cleaniest Duramax in history; it is also the most powerul, being released with 397 horsepower & 765 lb-ft of torque.
• Direct injection • Bosch high pressure common rail • 30,000 psi max injection pressure
Horsepower
397 hp @ 3,000 RPM
Torque
765 lb-ft @ 1,600 RPM
2007.5 – 2010 Duramax LMM
Quick Identifier:
LMMs were used from 2007.5-2010. Ways to identify this engine: – Exposed injectors and injector harnesses – Variable veined turbo charger – No FICM (fuel injection control module) on the passenger side valve cover – EGR cooler is rectangular
Nearly identical to the LBZ, the LMM debuted midway into the 2007 model year (2007.5). The slight variations between the LBZ and LMM gave the LMM a small boost in power output. The LMM features new emissions equipment that meet strict new diesel emission laws, and is currently in production today. Using a diesel particulate filter (DPF) and active regeneration technology, the LMM cut particulate matter emissions by 90 percent over the previous generation.
Years Produced
2007.5 – 2010
Displacement
403 cubic inches, 6.6 liters
Configuration
90 degree V8
Compression Ratio
16.8:1
Bore
4.06 inches
Stroke
3.90 inches
Aspiration
Intercooler & variable geometry turbocharger
Valvetrain
OHV, 4 valves per cylinder
Injection
26,000 psi Bosch high pressure common rail w/ CP3 injection pump
Horsepower
365 hp @ 3,100 RPM
Torque
660 lb-ft @ 1,800 RPM
2006 – 2007 Duramax LBZ
Quick Identifier:
LBZs were used from 2006-2007. Ways to identify this engine: – Exposed injectors and injector harnesses – Variable vane turbo charger – No FICM (fuel injection control module) on the passenger side valve cover – EGR cooler is cylindrical
The LBZ replaced the LLY late in the 2006 model year and production continued through 2007. A large bump in output was seen with the introduction of the LBZ. Mechanically, the LBZ is very similar to the 2006 LLY model. The most significant difference between the LLY and LBZ is the computer controls. The LBZ features a much “wilder” tune, giving it a large increase in power horsepower and torque output.
Years Produced
2006 – 2007
Displacement
403 cubic inches, 6.6 liters
Configuration
90 degree V8
Compression Ratio
16.8:1
Bore
4.06 inches
Stroke
3.90 inches
Aspiration
• Variable geometry turbocharger (VGT) • air to air intercooler • 20 psi maximum boost pressure
Valvetrain
OHV, 4 valves per cylinder
Injection
• Direct injection, high pressure Bosch common rail injection system, CP3 injection pump • Maximum 26,000 psi injection pressure • Seven hole injectors
Horsepower
360 hp @ 3,200 RPM
Torque
650 lb-ft @ 1,600 RPM
2004.5 – 2005 Duramax LLY
Quick Identifier:
LLYs were used from 2004.5-2005. Ways to identify this engine: – Exposed injectors and injector harnesses – Variable vane turbo charger – Has FICM (fuel injection control module) on the passenger side valve cover – EGR cooler is cylindrical
The Duramax LLY was introduced in 2004 to replace the popular LB7. Like the LB7, the LLY utilizes a high pressure common rail direct injection system. The LLY was General Motors’ first attemp at implementing emission controls on a diesel engine to meet stricter emissions requirements in the future. The LLY adopted a variable geometry turbocharger (VGT) and exhaust gas recirculation (EGR) system to help reduce emissions. Huge changes to the LLY debuted in 2005, but the engines were mechanically identical.
Years Produced
2004.5 – 2005
Displacement
403 cubic inches, 6.6 liters
Configuration
90 degree V8
Compression Ratio
17.5:1 (16.8:1 in 2006)
Bore
4.06 inches
Stroke
3.90 inches
Aspiration
• Garrett variable geometry turbocharger (VGT) • air to air intercooler
Valvetrain
OHV, 4 valves per cylinder
Injection
• Direct injection • Bosch high pressure common rail, CP3 injection pump • 23,000 psi max injection pressure
LB7s were used from 2001-2004. Ways to identify this engine: – Injectors and injector harnesses under the valve covers – The FICM (fuel injection control module) will be located on the front of the passenger side valve cover
The LB7 Duramax was first introduced in 2001 and produced until 2004. The 32 valve, V8 design utilizes a high pressure common rail direct injection system. Due to the lack of emission equipment, the LB7 is considered one of the most sought after Duramax’s built, obtaining the best fuel mileage and having the simplest design.
Years Produced
2001 – 2004
Displacement
402 cubic inches, 6.6 liters
Configuration
90 degree V8
Compression Ratio
17.5:1
Bore
4.06 inches
Stroke
3.90 inches
Aspiration
• Turbocharger • air to air intercooler • Maximum boost: 20 psi
Valvetrain
OHV, 4 valves per cylinder
Injection
• Direct injection • Bosch high pressure common rail, CP3 injection pump • 23,000 psi max injection pressure
Horsepower
• 235 hp @ 2,700 RPM (2001) • 300 hp @ 3,100 RPM (2004)
The L5p was first introduced in 2017 and continued until 2019 with the 6 speed Allison option. The best way to identify this engine is the large turbo actuator on top of the VGT turbo as well as the large intake plenum that forms a “Y” connecting to each cylinder head individually. They also have a large SCR catalyst attached directly to the back of the turbine housing.
Direct injection, high-pressure common rail, Denso HP4 pump, Denso GS4 Gen-III solenoid fuel injectors
Horsepower
445 hp @ 2,800 rpm
Torque
910 lb-ft @ 1,600 rpm
Quick Identifier:
LMLs were used from 2011-2016. Ways to identify this engine: – Orange wire loom on electrical harness due to high voltage – Dual EGR coolers
The LML Duramax is released for 2011 model General Motors & Chevrolet HD trucks. The latest version of the 6.6L Duramax, the LML uses advanced emissions equipment, including the use of diesel exhaust fluid injection, to reduce nitrogen oxide emission levels by 63 percent over LMM powered trucks. This allows the LML to exceed currently mandated federal emissions requirements & meet future future requirements as well. Not only is the LML the cleaniest Duramax in history; it is also the most powerul, being released with 397 horsepower & 765 lb-ft of torque.
• Direct injection • Bosch high pressure common rail • 30,000 psi max injection pressure
Horsepower
397 hp @ 3,000 RPM
Torque
765 lb-ft @ 1,600 RPM
Quick Identifier:
LMMs were used from 2007.5-2010. Ways to identify this engine: – Exposed injectors and injector harnesses – Variable veined turbo charger – No FICM (fuel injection control module) on the passenger side valve cover – EGR cooler is rectangular
Nearly identical to the LBZ, the LMM debuted midway into the 2007 model year (2007.5). The slight variations between the LBZ and LMM gave the LMM a small boost in power output. The LMM features new emissions equipment that meet strict new diesel emission laws, and is currently in production today. Using a diesel particulate filter (DPF) and active regeneration technology, the LMM cut particulate matter emissions by 90 percent over the previous generation.
Years Produced
2007.5 – 2010
Displacement
403 cubic inches, 6.6 liters
Configuration
90 degree V8
Compression Ratio
16.8:1
Bore
4.06 inches
Stroke
3.90 inches
Aspiration
Intercooler & variable geometry turbocharger
Valvetrain
OHV, 4 valves per cylinder
Injection
26,000 psi Bosch high pressure common rail w/ CP3 injection pump
Horsepower
365 hp @ 3,100 RPM
Torque
660 lb-ft @ 1,800 RPM
Quick Identifier:
LBZs were used from 2006-2007. Ways to identify this engine: – Exposed injectors and injector harnesses – Variable vane turbo charger – No FICM (fuel injection control module) on the passenger side valve cover – EGR cooler is cylindrical
The LBZ replaced the LLY late in the 2006 model year and production continued through 2007. A large bump in output was seen with the introduction of the LBZ. Mechanically, the LBZ is very similar to the 2006 LLY model. The most significant difference between the LLY and LBZ is the computer controls. The LBZ features a much “wilder” tune, giving it a large increase in power horsepower and torque output.
Years Produced
2006 – 2007
Displacement
403 cubic inches, 6.6 liters
Configuration
90 degree V8
Compression Ratio
16.8:1
Bore
4.06 inches
Stroke
3.90 inches
Aspiration
• Variable geometry turbocharger (VGT) • air to air intercooler • 20 psi maximum boost pressure
Valvetrain
OHV, 4 valves per cylinder
Injection
• Direct injection, high pressure Bosch common rail injection system, CP3 injection pump • Maximum 26,000 psi injection pressure • Seven hole injectors
Horsepower
360 hp @ 3,200 RPM
Torque
650 lb-ft @ 1,600 RPM
Quick Identifier:
LLYs were used from 2004.5-2005. Ways to identify this engine: – Exposed injectors and injector harnesses – Variable vane turbo charger – Has FICM (fuel injection control module) on the passenger side valve cover – EGR cooler is cylindrical
The Duramax LLY was introduced in 2004 to replace the popular LB7. Like the LB7, the LLY utilizes a high pressure common rail direct injection system. The LLY was General Motors’ first attemp at implementing emission controls on a diesel engine to meet stricter emissions requirements in the future. The LLY adopted a variable geometry turbocharger (VGT) and exhaust gas recirculation (EGR) system to help reduce emissions. Huge changes to the LLY debuted in 2005, but the engines were mechanically identical.
Years Produced
2004.5 – 2005
Displacement
403 cubic inches, 6.6 liters
Configuration
90 degree V8
Compression Ratio
17.5:1 (16.8:1 in 2006)
Bore
4.06 inches
Stroke
3.90 inches
Aspiration
• Garrett variable geometry turbocharger (VGT) • air to air intercooler
Valvetrain
OHV, 4 valves per cylinder
Injection
• Direct injection • Bosch high pressure common rail, CP3 injection pump • 23,000 psi max injection pressure
LB7s were used from 2001-2004. Ways to identify this engine: – Injectors and injector harnesses under the valve covers – The FICM (fuel injection control module) will be located on the front of the passenger side valve cover
The LB7 Duramax was first introduced in 2001 and produced until 2004. The 32 valve, V8 design utilizes a high pressure common rail direct injection system. Due to the lack of emission equipment, the LB7 is considered one of the most sought after Duramax’s built, obtaining the best fuel mileage and having the simplest design.
Years Produced
2001 – 2004
Displacement
402 cubic inches, 6.6 liters
Configuration
90 degree V8
Compression Ratio
17.5:1
Bore
4.06 inches
Stroke
3.90 inches
Aspiration
• Turbocharger • air to air intercooler • Maximum boost: 20 psi
Valvetrain
OHV, 4 valves per cylinder
Injection
• Direct injection • Bosch high pressure common rail, CP3 injection pump • 23,000 psi max injection pressure
Horsepower
• 235 hp @ 2,700 RPM (2001) • 300 hp @ 3,100 RPM (2004)
