HP Tuners - Part VII - Set Fuel Tank Capacity.
This is a benign change that I just like to do for the sake of completion. Most likely our trucks fuel tanks (16 gallons in my case) won't match the donor trucks fuel tank capacity (25 gallons). So I like to make this change in HP Tuners although we use our stock gauges to monitor fuel levels and not the PCM output but there are some third party gauges that do offer Fuel Level readings, like my Edge Insight CTS2.
1. On your laptop launch the Editor. Open the file we saved in Step 3 of Part VI. (Our last saved file is always our starting point).
2. Make changes in the Editor, this time we will make changes only to the Fuel Tank/Gauge Capacity settings found under the Fuel Sys tab. Enter 16 in the box next to Capacity and Primary Capacity, using your fuel tank capacity numbers of course. Again this may not do anything, unless we have a body module or an after market gauge, but I just sleep better at night knowing the PCM knows the proper size of my tank, ha ha.
3. Save the changes you made to a new file and call it something like "13 - Set Fuel Tank Capacity"
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.