[Gregski]

HP Tuners - Part VI - Disable the Speed Limiters.

There are settings in the PCM that turn off fuel delivery above a certain speed. In my case it was set to 98 miles per hour, your settings may differ. Now we all know you can't run moonshine at 98 MPH, ha ha, so let's increase that limit, essentially disabling the limiter.

1. On your laptop launch the Editor. Open the file we saved in Step 3 of Section F. (Our last saved file is always our starting point).

2. Make changes in the Editor, this time we will make changes only to the Speed Limiter settings found under the Speedo\Limiter tab. Enter 255 in the box next to Speed Limiter under Limit By Fuel. This means do not turn off fuel delivery to the engine until above 255 MPH. I have a drive by cable throttle, but it don't hurt to do the same under both boxes under the Limit By Airflow heading: ETC Speed Limiter and ETC Speed Limiter 2, I believe those are for Electronic Throttle Controls aka "drive by wire". (Additional instructions with each pic)

3. Save the changes you made to a new file and call it something like "12 - Turn Off Speed Limiter"

4. In your truck, hook up your HP Tuner to the OBDII port and then your USB cable to your laptop, turn the key to the ON position, launch the Editor program, and simply write the new changes to the PCM.

Note: sometimes you have to write the entire tune file to the PCM, sometimes it is perfectly happy with only writing what's changed, more on this later.

More words with each pic below.