Onto another new feature due out soon within the next NVH beta build, this is called “Graphing PID’s” or in plain English “Graphing OBD-II parameter identification codes” (Not sure that is any clearer)
In a nutshell, Parameter ID’s are standardised codes sent via a Scan Tool onto the relevant vehicle network to request specific data.
A technician requires Accelerator Pedal Position Sensor data:
The Parameter ID or “PID” formula for requesting Accelerator Pedal Position Sensor data is A*100/255
The Scan Tool will place the required PID onto the vehicle network and the node (PCM in this case) will surrender the Accelerator Pedal Position Sensor data which in turn will then be displayed on the Scan Tool screen.
So why is this relevant to NVH and how could this assist with such diagnosis?
At present the NVH software utilises these PID’s to request engine and road speed data via the J2534 OBD interface. (MongoosePro ISO/CAN 2)
Both engine and road speed are graphed in the signal history in order to identify the vehicle condition under a variety of noise and vibration symptoms.
Until now, the NVH software would only request engine and road speed data but now we can request a number of OBD-II parameters using available PID’s stored within the PID library. To access the PID library click on the Vehicle Information tab and select Configure PIDs where Available PID’s can be selected then added to the Current Capturing PIDs table
To add Accelerator Pedal Position Sensor to your existing ODB-II parameter data, click on Accelerator Pedal Position Sensor in the Available PID Library and select “Start Capturing” then “Apply Changes”
Should you wish to edit a PID (using Accelerator Position Sensor as an example) double click on any PID in the Available PID Library where the Edit PID dialogue box will appear. Here you can edit any of the data including the PID formula, whilst also confirming successful verification of the PID via the displayed “Green Tick” (Engine On and J2534 interface connected)
The new Configure PIDs feature includes the option to Create a PID assuming you have the relevant PID data/formula. (Engine On and J2534 interface connected)
In the example below we have created a PID for “Throttle position” that was not originally found in the Available PID Library. (For PID data refer to the relevant 3rd party technical information that is often manufacturer specific) Fill out the relevant PID data and click OK when complete. Your new “Created” PID will now appear in the Available PID Library for selection as above
Finally PID’s can be Imported or Exported using the relevant buttons to the right of the Available PID Library. (Import / Export) Here you can create and save your model specific PID’s to your local PC and share with other users (Export).
All created PID’s are saved as .pdpid files and of course can be imported should you receive a PID via email attachment etc.
At present, to view your selected PID’s in relation to noise and vibration data you will need to select the “Time Domain” option where Accelerometer and Microphone data are displayed with reference to time. Such PID data may well be relevant if noise or vibration is linked to “Engine load” / “Engine Temperature” for engine mechanical noises or “MAF” / “Accelerator Pedal Position Sensor” for air intake noise.
The image above indicates how the relevant PID’s would be displayed against accelerometer data (X axis). The options here are too numerous to list as the user could select the desired accelerometer axis or Mic data against the desired PID.
I hope this helps, take care…….Steve