How to Read, License, and Flash an ECM

Modified on Tue, 21 Nov 2023 at 01:32 PM

Before you begin, ensure that the vehicle is as free of mechanical problems as possible. If there is a mechanical issue with the vehicle, it may affect performance and any performance data you want to monitor could be impacted. This makes it very difficult to tune the vehicle effectively.

IMPORTANT:  Reading a vehicle will clear any DTCs (Diagnostic Trouble Codes) from the vehicle's computer, resulting in a loss of the troubleshooting information they contain. ALWAYS check the vehicle for DTCs before you do anything else. See Reading and Clearing DTCs for more information.

Reading the Vehicle

When you read a vehicle, you are transferring calibration information from the control module(s) in your vehicle to VCM Editor. The read process will automatically detect the presence of relevant VCMs in the vehicle and read them all in sequence. The various status messages and the progress bar give information about the current state of the read.

CAUTION: Ensure that the vehicle battery is charged before proceeding (keeping the battery attached to a charger during the procedure is recommended). Although it should not be possible to harm any of the vehicle's control modules during the read process, vehicle controllers can be left in an odd state if a power loss occurs.

To read the VCM, follow these steps:

1.Connect your HP Tuners interface device to a laptop with VCM Suite installed. Then, connect the device to the vehicle's OBD-II diagnostic port. See Connecting to the Vehicle for more information.
2.If VCM Scanner is open, close it before proceeding.
3.Open VCM Editor.
4.If a tune file is open, close it by selecting File > Close in the menu bar.
5.Put the key in the ignition and turn to the ON position. Do not start the vehicle.

NOTE: Some vehicles require special procedures to be put in the correct state. See Putting a Vehicle in the "ON" State for more information. 

6.Make sure the doors are closed and all accessories are turned off.

CAUTION: Do not use any vehicle accessories, including the door locking mechanism, during reading or writing procedures.

7.In VCM Editor, select Flash > Read Vehicle.

8.The Vehicle Reader window appears. Wait 10 to 15 seconds.
9.Click the Read button.

10.Allow the PC to read the VCM until the status bar indicates the read had completed.

NOTE: For vehicles with multiple VCMs (e.g. LS2 A4 vehicles), there is a 15-second pause between reading each VCM.

11.Turn off the ignition and unplug the interface cable.
12.The file will automatically open in VCM Editor.

NOTE: If this is the initial read of the stock VCM, we strongly recommend that you save (and backup) the file before any modifications are made. You may wish to restore your vehicle to the stock tune at a later date.

Writing a Tune Back to the Vehicle

Before you begin, ensure that:

The vehicle has a fully charged battery. Connecting the vehicle's battery to a battery charger before writing a tune is recommended.
Your laptop has a fully charged battery.

Follow these steps to write a tune back to the vehicle:

1.Connect your HP Tuners interface device to a laptop with VCM Suite installed. Then, connect the device to the vehicle's OBD-II diagnostic port. See Connecting to the Vehicle for more information.
2.If VCM Scanner is open, close it before proceeding.
3.Open VCM Editor.
4.Open VCM Editor. Ensure a valid file for this vehicle is currently open (this could be the file you just read).
5.Select Write Vehicle from the Flash menu.

NOTE: The first time you attempt to write to each vehicle, you will be prompted to purchase a license for that vehicle.

6.Turn the vehicle ignition to the ON (or RUN) position. Do not start the vehicle.

NOTE: Some vehicles require special procedures to be put in the correct state. See See Putting a Vehicle in the "ON" State for more information..

7.Make sure the doors are closed and all accessories are turned off.

CAUTION: Do not use any vehicle accessories, including the door locking mechanism, during reading or writing procedures.

8.Wait 10 to 15 seconds.
9.Click the Write button.
10.Allow the PC to write the VCM until the status bar indicates the write has been completed.
11.Turn off the ignition and unplug the interface cable. Wait at least 15 seconds before restarting the vehicle.
12.The new calibration has now been written to the vehicle.

CAUTION:

Do not disrupt the programming session.
Do not open vehicle doors or use vehicle accessories.
Do not program vehicles with battery voltage lower than 11.5 Volts.
Do not attempt to use the vehicle to power or charge the laptop. If it is necessary to provide additional battery power to the laptop, use an external battery that is not connected to the vehicle.

VCM Recovery

When rewriting the VCM, critical components of the VCM software must be erased and re-written. If the VCM loses power during the writing of these critical system components, the VCM may become unrecoverable. Do not power down the VCM under any circumstances during a write failure using these advanced options.

Rewrite Entire (selected vehicles only)

This is a useful feature for the tuner shop or mail order tuner and doesn't apply much to a single-vehicle tuner. What this can allow you to do is program a VCM that came from another vehicle for your specific vehicle type. You must make sure that the VCM hardware matches. This is a very powerful feature and must be used with caution. If you write a VCM with a file that doesn't belong on it, you could damage the VCM and cause it to be unrecoverable. It is not available for all vehicle types.

"Write VCM" failed and now my car won't start, what do I do?

Don't panic. An error during the write process has occurred. Follow these guidelines:

Make sure the vehicle has sufficient battery voltage for programming.
Make sure your laptop has sufficient power.
Make sure all communications cables are connected firmly.
DO NOT pull your VCM's fuse or disconnect battery power in an attempt to correct the problem.
Restart VCM Editor and open up the same file you wrote to the VCM when the error occurred. It is very important that you use the same file. Try to Write VCM again.
If the problem persists, please Contact Customer Support.

 

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