When switch-on-the-fly tuning is included, you can change between the available power levels using the factory steering-wheel controls.

The available tune levels are:

• Optimized Stock
• Heavy Tow
• Light Tow
• Sport Economy
• Race / Performance

To change tunes:

1. Press Cruise Control Cancel.
2. Use the Cruise Up/Down controls to cycle through the available tune positions.
3. Press Cancel again to select the desired tune.

The selected tune is indicated by the number of times the glow plug light flashes.

Depending on the model year, the truck may display either:

• positions 0–4, or
• positions 1–5

There is no difference in function between the two systems.

As the number of flashes increases, so does the power level. The lowest position is Optimized Stock, with Race / Performance as the highest.

Optimized Stock

• Factory-like driving dynamics
• Similar power output to stock
• Lowest power position

Heavy Tow

• Intended for towing loads up to the vehicle's GVWR
• Approximately +90 RWHP
• Approximately +120 ft-lbs of torque over factory
• Broad torque curve to improve drivability while towing
• Balanced for towing and everyday use
• Can still be enjoyed unloaded

Light Tow

• Intended for towing loads up to approximately 8,000 lbs
• Approximately +110 RWHP
• Approximately +200 ft-lbs of torque over factory
• Designed for boats, smaller trailers, tractors, and similar loads
• Good balance between towing ability and sportier unloaded driving

Sport Economy

• Intended for unloaded daily driving
• Good for normal town and highway use
• Approximately +140 RWHP
• Approximately +300 ft-lbs of torque over factory
• Brings the truck to approximately the 550 RWHP range

Race / Performance

• Maximum-performance calibration intended to make full use of the factory turbo
• Approximately +190 RWHP
• Approximately +500 ft-lbs of torque over factory
• Approximately 600 RWHP / 1,360 ft-lbs
• Up to approximately 620 RWHP / 1,380 ft-lbs with a WC Fab turbo mouthpiece

1. If installing aftermarket exhaust components, we suggest flashing the tune before installing the parts. This helps prevent the truck from entering a fault state before the tuning has been installed.
2. Make sure there are no DEF-level or air-filter warnings present before flashing.
   Address these warnings before tuning. Existing warnings can sometimes remain after programming and become more difficult to clear.
3. On 2020+ trucks, make sure the TCM calibration is up to date through your dealership if we are not supplying TCM tuning.
   An outdated or improperly updated TCM calibration can result in a Reduced Power in X Miles warning when paired with the current ECM operating system.
4. We recommend using a battery charger while reading or programming the vehicle, especially if battery condition is unknown.
   Loss of vehicle power during programming can cause damage.
5. If your vehicle requires an ECM unlock, replacement ECM, or E41 upgrade/unlock tool, complete the applicable procedure before attempting to read or write the truck.

Some early L5P trucks require additional ECM hardware or unlock procedures.

For 2017–2018 L5P trucks with a locked ECM, install the unlocked ECM or connect the appropriate ECM unlock/upgrade hardware before reading or performing the initial flash.

Later supported L5P applications can be accessed without replacing the ECM.

If you are using the E41 upgrade/unlock tool, keep it connected whenever instructed during the initial read and first programming procedure.

Follow the instructions supplied with your specific unlock hardware if they differ from the general instructions below.

This is our preferred method.

It provides access to VCM Editor, VCM Scanner, special functions, module replacement functions, and the widest range of troubleshooting options.

MPVI users will need the latest VCM Suite Beta.

Download VCM Suite Beta

SFG Tuner users who require RTD Flasher can download it here:

Download RTD Flasher

When communicating with the truck, the key or push-button ignition must be in the ON/RUN position with the engine NOT running. Accessory mode will not work.

If the truck has a replacement ECM, replacement TCM, or both, complete the applicable VCM Scanner replacement procedure below before taking the read that will be sent to us. Any read required for a replaced controller must come from the replacement controller, not the original one.

ECM Swap Instructions

TCM Swap Instructions

If the truck has a replacement ECM or TCM, complete the applicable ECM + TCM Swap Trucks instructions above before reading.

1. Connect your tuning device to the truck's OBD-II port.
2. Connect the tuning device to your Windows computer.
3. If your truck requires an unlocked ECM or ECM upgrade/unlock tool, make sure it is installed or connected before continuing.
4. Open VCM Editor Beta.

5. If this is the first time the interface has been used on this computer, go to:

   Help → Resync Interface

6. Turn the ignition to ON/RUN, with the engine NOT running.

   Accessory mode will not work.

7. Go to:

   Flash → Read Vehicle

8. Click Gather Info.
9. Allow VCM Editor to finish identifying the modules in the vehicle.
10. Set the desired module dropdown to Read Entire.

For the L5P engine computer, the ECM is the E41.

11. Click Read.
12. Allow the read process to complete without disconnecting the truck, laptop, or tuning device.
13. HP Tuners may generate the appropriate stock file for your vehicle through its servers.
14. Press OK when prompted and save the file somewhere you can easily find it.

The default file location is commonly:

Documents → HP Tuners → Logs and Tunes

15. Send the saved file to Support@SpeedFarmGarage.com, or reply to your order email with the file attached.

We will then prepare your tuned file and send it to you by email.

Credits will also be applied as required during this process.

Be sure you have read the Important Before Starting section above before programming the vehicle.

If a VATS OFF file was supplied for a replacement ECM: use it as instructed to commission/program the immobilizer. Any required injector coding must be completed while the ECM is on a stock ECM calibration; injector coding cannot be performed with the final VATS ON tune installed. Once immobilizer programming and any required injector coding are complete, proceed with the normal VATS ON tune file supplied for the truck unless we specifically instruct otherwise.

1. Download the tune file we supplied by email.
2. If you are using an ECM upgrade/unlock tool, connect it before continuing.
3. Open VCM Editor Beta.

4. Go to:

   File → Open

5. Select the tune file we supplied.

6. Go to:

   Help → Resync Interface

This allows the interface to synchronize its current licensing and credit information.

7. Turn the ignition to ON/RUN, with the engine NOT running.

   Accessory mode will not work.

8. Go to:

   Flash → Write Vehicle

9. If VCM Editor displays a License Options button, select it and license the required module.
10. For the modules being programmed, select Write Entire unless your specific instructions tell you otherwise.
11. Click Write Vehicle.
12. Programming will now begin.

Do not disconnect the tuning device, laptop, unlock hardware, or vehicle power while programming is in progress.

If an E41 upgrade/unlock procedure is being performed at the same time, the first programming operation may take significantly longer than a normal tune flash.

13. Follow all instructions shown by VCM Editor.
14. Wait until the write has completely finished.
15. Once programming is complete, power the truck off.
16. Remove temporary ECM upgrade/unlock hardware if applicable.
17. Reinstall any fuse or factory connection that was removed as part of the unlock procedure.

Trucks retaining their original ECM are now ready for any remaining checks before driving.

The TDN App can be used with compatible HP Tuners and SFG tuning devices when a Windows computer is not available.

TDN does NOT support the ECM or TCM replacement functions described above.

If the truck has a replacement ECM or TCM, complete the applicable ECM + TCM Swap Trucks procedure using Windows and VCM Scanner before using TDN for normal reading or flashing.

Android

Download TDN for Android

Apple / iPhone

Download TDN for iPhone

1. Download and install the TDN App.
2. Open TDN.
3. Register an HP Tuners account, or sign in to your existing account.
4. Go to Tools.
5. Select the appropriate First Time Setup option for your tuning device.
6. Follow the app's instructions to connect to the tuning device.
7. Allow the tuning device to update if prompted.

The tuning device should be connected to a vehicle during First Time Setup as instructed by TDN.

The First Time Setup procedure itself does not read or write the vehicle calibration.

8. Go to the Account page.
9. Select Link Tuner.
10. Enter tuner link code:

ZSJC-1058

Before beginning, make sure the ignition is ON/RUN with the engine NOT running.

1. Connect your tuning device to the truck.
2. Open the TDN App.
3. Complete First Time Setup if it has not already been performed.
4. Go to Flash.
5. Select Read Vehicle.
6. Follow the instructions shown in the app.
7. Allow TDN to complete the read without disconnecting the vehicle or tuning device.

The stock read will be saved in TDN and uploaded through the app.

8. Notify us once the stock read has uploaded.

Once we have completed your tune and uploaded it, TDN will notify you if app notifications are enabled.

Before beginning, place the ignition in ON/RUN with the engine NOT running.

1. Connect the tuning device to the truck.
2. Open the TDN App.
3. Go to Flash.
4. Select Sync Files.
5. Wait for the available tune files to synchronize.
6. Select the tune you want to install.
7. Press and hold the Write button.
8. Select Write Entire.
9. Begin programming.
10. Do not disconnect the tuning device or interrupt vehicle power while the flash is in progress.
11. Follow any ignition ON/OFF instructions displayed by TDN.
12. Wait until TDN confirms that programming has completed.

Once finished, cycle vehicle power as instructed.

The vehicle is now ready for any additional vehicle-specific checks.

Fuel Gauge Reads Empty After Modifying Exhaust Sensors

The CAN communication path for the fuel tank module passes through components in the NOx sensor / main DEF harness area.

If the fuel gauge reads empty after hardware changes, check the associated wiring and CAN continuity and repair any connection issue as required.

DEF Level Low Warning

Tuning cannot make the truck report a full DEF tank when the vehicle already believes the DEF level is low.

Make sure the DEF level and related warnings are correct before tuning.

Service Air Filter — 2020+ Trucks

If a Service Air Filter message is present:

1. Connect with VCM Scanner.
2. Open Vehicle Controls & Special Functions.
3. Perform the applicable Air Filter Reset.

Alternatively, return the truck to stock, perform the air-filter reset, and then reinstall the tune.

Reduced Power in X Miles — 2020+ Trucks

This warning can occur when the TCM calibration is not compatible with the updated ECM operating system.

The applicable GM TCM calibration update may not have been performed, or may not have been completed correctly.

If we are not providing TCM tuning, consult a dealership about updating the TCM calibration.

Alternatively, unlocked TCM hardware and TCM tuning can be purchased so that we can supply the appropriate updated transmission calibration.

We cannot provide a TCM calibration update without TCM tuning.

HP Tuners also provides its own guide to reading, licensing, and flashing an ECM:

HP Tuners — How to Read, License and Flash an ECM

If you encounter a problem that is not covered here, contact us and include:

• truck year
• tuning device being used
• ECM/TCM hardware configuration
• exact step where the problem occurred
• any warnings or error messages shown on the truck, TDN, VCM Editor, or VCM Scanner