I have gotten a few people email me about wiring a wideband up for logging using the AC pressure sensor. If I do an elaborate How-To on this can it be made into a sticky? I have to go through all the steps time and time again for people on this. I think a lot of people get into HPtuners without purchasing the EIO cable and dont want to pay for the upgrade after they buy a wideband. I was just wondering if I could get a sticky made out of this. I need someone to host it as well.
So here it goes... With Pics!
1. First thing to do is track down the AC Pressure sensor. It is located on the passenger side right up in front of the coolant reservoir. Here is a picture of what you are looking for.
Click the image to open in full size.
2. Now you have three choices on how to do this next step.
1.* The easiest way to do this is to install a switch in this wire you just cut. This way you can switch the output on the wire from the wideband to the AC when you arent tuning. It will take a 3pole switch that has 2 inputs and one output.
2.* If you dont want to run AC just wire the wideband in and leave the sensor unplugged. This one is not for me, AC is a must!
3.* Install quick connect ends where you can unplug the wideband and plug the AC Sensor back up.
3. Of course you will have to wire the Wideband as well. Once everything is wired up check to make sure the wideband is working properly on the gauge display. Once operation is correct we can go on to getting this thing to read into HPtuners.
4. This is very simple to do it sounds harder than it really is. Here it is step by step.
1.- Open VCM Scanner
2.- Open the Table Display
3.- Right click the table
4.- Left click insert
5.- Down at the bottom you will see User Defined if there is a + sign next to it click the + sign and you will see configure user defined.
6.- Double Left click configure user defined
Here is a pic
Click the image to open in full size.
7.- Now click one of the undefined labels and insert a name for your wideband.
Click the image to open in full size.
8.- Now we need to input the function string that will take the voltage coming from the wideband output and convert it to AFR. At the bottom of this screen you will see a function line. Enter ([PID. 7101]/.5)+10, you will notice mine is 9.8... we will get to this in a minute for now just put 10.
Click the image to open in full size.
9.- Now the reason my formula is 9.8 is because of voltage drop. When doing some researching I figured out that my wideband was reading .2 different on my HPtuners than the gauge display was showing. So using the formula I basically calibrated my laptop to read the same as my gauge. So you need to scan the car and see if there is any difference, if there is adjust it the way I did.
10. Now lets open the scanner, connect to the car and scan to ensure the PID is working. If you have a switch installed make sure you have it on the wideband. If everything is working good lets move on to creating a histogram.
Creating the Histogram for the wideband
1.- Now that we have created the function already this part is very simple. Open the Scanner, open the histogram display.
2.- To the right of the number 8 you will see a configure button. Click that.
3.- The easiest way to do this is to use the wideband configuration thats default on the scanner. Click the wideband input, I am wanting to think its the #6. I will post pics of this setup tonight.
4.- You will then see how the wideband is default setup. If you look where it says sensor you will see that next to the sensor it says air fuel ratio. To the right of that you will see PID:, Click next to where it says PID:.
5.- You should see the custom PID we made earlier for the wideband. It will be listed under the user configured and will be named the name you created earlier. Now double click the custom pid you created and hit the floppy disk in the top left corner to commit the changes.
6.- Do another scan and ensure everything is working properly.
Its back to work for me, but next we tackle creating an air fuel ratio %error histogram. Pics coming soon!
Read more:
Connecting wideband via EGR or A/C Pressure in HP Tuners - Corvette Forum
